Misc/NEWS

+++++++++++
Python News
+++++++++++

What's New in Python 3.3.0 Beta 2?
==================================

*Release date: xx-xxx-2012*

Core and Builtins
-----------------

- Issue #15404: Refleak in PyMethodObject repr.

- Issue #15394: An issue in PyModule_Create that caused references to
  be leaked on some error paths has been fixed.  Patch by Julia Lawall.

- Issue #15368: An issue that caused bytecode generation to be
  non-deterministic has been fixed.

- Issue #15202: Consistently use the name "follow_symlinks" for
  new parameters in os and shutil functions.

- Issue #15314: __main__.__loader__ is now set correctly during
  interpreter startup

- Issue #15111: When a module imported using 'from import' has an ImportError
  inside itself, don't mask that fact behind a generic ImportError for the
  module itself.

- Issue #15293: Add GC support to the AST base node type.

- Issue #15291: Fix a memory leak where AST nodes where not properly
  deallocated.

- Issue #15110: Fix the tracebacks generated by "import xxx" to not show
  the importlib stack frames.

- Issue #15020: The program name used to search for Python's path is now
  "python3" under Unix, not "python".

- Issue #15033: Fix the exit status bug when modules invoked using -m swith,
  return the proper failure return value (1). Patch contributed by Jeff Knupp.

- Issue #15229: An OSError subclass whose __init__ doesn't call back
  OSError.__init__ could produce incomplete instances, leading to crashes
  when calling str() on them.

- Issue 15307: Virtual environments now use symlinks with framework builds
  on Mac OS X, like other POSIX builds.

Library
-------

- Issues #10017 and #14998: Fix TypeError using pprint on dictionaries with
  user-defined types as keys or other unorderable keys.

- Issue #15397: inspect.getmodulename() is now based directly on importlib
  via a new importlib.machinery.all_suffixes() API.

- Issue #14635: telnetlib will use poll() rather than select() when possible
  to avoid failing due to the select() file descriptor limit.

- Issue #15180: Clarify posixpath.join() error message when mixing str & bytes

- Issue #15343: pkgutil now includes an iter_importer_modules implementation
  for importlib.machinery.FileFinder (similar to the way it already handled
  zipimport.zipimporter)

- Issue #15314: runpy now sets __main__.__loader__ correctly

- Issue #15357: The import emulation in pkgutil is now deprecated. pkgutil
  uses importlib internally rather than the emulation

- Issue #15233: Python now guarantees that callables registered with
  the atexit module will be called in a deterministic order.

- Issue #15238: shutil.copystat now copies Linux "extended attributes".

- Issue #15230: runpy.run_path now correctly sets __package__ as described
  in the documentation

- Issue #15315: Support VS 2010 in distutils cygwincompiler.

- Issue #15294: Fix a regression in pkgutil.extend_path()'s handling of
  nested namespace packages.

- Issue #15056: imp.cache_from_source() and source_from_cache() raise
  NotImplementedError when sys.implementation.cache_tag is set to None.

- Issue #15256: Grammatical mistake in exception raised by imp.find_module().

- Issue #5931: wsgiref environ variable SERVER_SOFTWARE will specify an
  implementation specific term like Cpython, Jython instead of generic "Python"

- Issue #13248: Remove obsolete argument "max_buffer_size" of BufferedWriter
  and BufferedRWPair, from the io module.

- Issue #13248: Remove obsolete argument "version" of argparse.ArgumentParser.

- Issue #14814: implement more consistent ordering and sorting behaviour
  for ipaddress objects

- Issue #14814: ipaddress network objects correctly return NotImplemented
  when compared to arbitrary objects instead of raising TypeError

- Issue #14990: Correctly fail with SyntaxError on invalid encoding
  declaration.

- Issue #14814: ipaddress now provides more informative error messages when
  constructing instances directly (changes permitted during beta due to
  provisional API status)

- Issue #15247: FileIO now raises an error when given a file descriptor
  pointing to a directory.

- Issue #15261: Stop os.stat(fd) crashing on Windows when fd not open.

- Issue #15166: Implement imp.get_tag() using sys.implementation.cache_tag.

- Issue #15210: Catch KeyError when imprortlib.__init__ can't find
  _frozen_importlib in sys.modules, not ImportError.

- Issue #15030: importlib.abc.PyPycLoader now supports the new source size
  header field in .pyc files.

- Issue #5346: Preserve permissions of mbox, MMDF and Babyl mailbox
  files on flush().

- Issue #10571: Fix the "--sign" option of distutils' upload command.
  Patch by Jakub Wilk.

- Issue #9559: If messages were only added, a new file is no longer
  created and renamed over the old file when flush() is called on an
  mbox, MMDF or Babyl mailbox.

- Issue 10924: Fixed mksalt() to use a RNG that is suitable for cryptographic
  purpose.

C API
-----

- Issues #15169, #14599: Strip out the C implementation of
  imp.source_from_cache() used by PyImport_ExecCodeModuleWithPathnames() and
  used the Python code instead. Leads to PyImport_ExecCodeModuleObject() to not
  try to infer the source path from the bytecode path as
  PyImport_ExecCodeModuleWithPathnames() does.

Extension Modules
-----------------

- Issue #6493: An issue in ctypes on Windows that caused structure bitfields
  of type ctypes.c_uint32 and width 32 to incorrectly be set has been fixed.

- Issue #15194: Update libffi to the 3.0.11 release.

Tools/Demos
-----------

- Move importlib.test.benchmark to Tools/importbench.

- Issue #12605: The gdb hooks for debugging CPython (within Tools/gdb) have
  been enhanced to show information on more C frames relevant to CPython within
  the "py-bt" and "py-bt-full" commands:
    * C frames that are waiting on the GIL
    * C frames that are garbage-collecting
    * C frames that are due to the invocation of a PyCFunction

Documentation
-------------

- Issue #15230: Clearly document some of the limitations of the runpy
  module and nudge readers towards importlib when appropriate.

- Issue #15053: Copy Python 3.3 import lock change notice to all relevant
  functions in imp instead of just at the top of the relevant section.

- Issue #15288: Link to the term "loader" in notes in pkgutil about how things
  won't work as expected in Python 3.3 and mark the requisite functions as
  "changed" since they will no longer work with modules directly imported by
  import itself.

- Issue #13557: Clarify effect of giving two different namespaces to exec or
  execfile().

Tests
-----

- Issue #15168: Move importlib.test to test.test_importlib.

- Issue #15091: Reactivate a test on UNIX which was failing thanks to a
  forgotten importlib.invalidate_caches() call.

- Issue #15230: Adopted a more systematic approach in the runpy tests.

- Issue #15300: Ensure the temporary test working directories are in the same
  parent folder when running tests in multiprocess mode from a Python build.
  Patch by Chris Jerdonek.

- Issue #15284: Skip {send,recv}msg tests in test_socket when IPv6 is not
  enabled. Patch by Brian Brazil.

- Issue #15277: Fix a resource leak in support.py when IPv6 is disabled.
  Patch by Brian Brazil.

Build
-----

- Issue #14330: For cross builds, don't use host python, use host search paths
  for host compiler.

- Issue #15235: Allow Berkley DB versions up to 5.3 to build the dbm module.

- Issue #15268: Search curses.h in /usr/include/ncursesw.


What's New in Python 3.3.0 Beta 1?
==================================

*Release date: 27-Jun-2012*

Core and Builtins
-----------------

- Fix a (most likely) very rare memory leak when calling main() and not being
  able to decode a command-line argument.

- Issue #14815: Use Py_ssize_t instead of long for the object hash, to
  preserve all 64 bits of hash on Win64.

- Issue #12268: File readline, readlines and read() or readall() methods
  no longer lose data when an underlying read system call is interrupted.
  IOError is no longer raised due to a read system call returning EINTR
  from within these methods.

- Issue #11626: Add _SizeT functions to stable ABI.

- Issue #15146: Add PyType_FromSpecWithBases. Patch by Robin Schreiber.

- Issue #15142: Fix reference leak when deallocating instances of types
  created using PyType_FromSpec().

- Issue #15042: Add PyState_AddModule and PyState_RemoveModule. Add version
  guard for Py_LIMITED_API additions. Patch by Robin Schreiber.

- Issue #10053: Don't close FDs when FileIO.__init__ fails. Loosely based on
  the work by Hirokazu Yamamoto.

- Issue #15096: Removed support for ur'' as the raw notation isn't
  compatible with Python 2.x's raw unicode strings.

- Issue #13783: Generator objects now use the identifier APIs internally

- Issue #14874: Restore charmap decoding speed to pre-PEP 393 levels.
  Patch by Serhiy Storchaka.

- Issue #15026: utf-16 encoding is now significantly faster (up to 10x).
  Patch by Serhiy Storchaka.

- Issue #11022: open() and io.TextIOWrapper are now calling
  locale.getpreferredencoding(False) instead of locale.getpreferredencoding()
  in text mode if the encoding is not specified. Don't change temporary the
  locale encoding using locale.setlocale(), use the current locale encoding
  instead of the user preferred encoding.

- Issue #14673: Add Eric Snow's sys.implementation implementation.

- Issue #15038: Optimize python Locks on Windows.

Library
-------

- Issue #15187: Bugfix: remove temporary directories test_shutil was leaving
  behind.

- Issue #15177: Added dir_fd parameter to os.fwalk().

- Issue #15176: Clarified behavior, documentation, and implementation
  of os.listdir().

- Issue #15061: Re-implemented hmac.compare_digest() in C to prevent further
  timing analysis and to support all buffer protocol aware objects as well as
  ASCII only str instances safely.

- Issue #15164: Change return value of platform.uname() from a
  plain tuple to a collections.namedtuple.

- Support Mageia Linux in the platform module.

- Issue #11678: Support Arch linux in the platform module.

- Issue #15118: Change return value of os.uname() and os.times() from
  plain tuples to immutable iterable objects with named attributes
  (structseq objects).

- Speed up _decimal by another 10-15% by caching the thread local context
  that was last accessed. In the pi benchmark (64-bit platform, prec=9),
  _decimal is now only 1.5x slower than float.

- Remove the packaging module, which is not ready for prime time.

- Issue #15154: Add "dir_fd" parameter to os.rmdir, remove "rmdir"
  parameter from os.remove / os.unlink.

- Issue #4489: Add a shutil.rmtree that isn't susceptible to symlink attacks.
  It is used automatically on platforms supporting the necessary os.openat()
  and os.unlinkat() functions. Main code by Martin von Löwis.

- Issue #15156: HTMLParser now uses the new "html.entities.html5" dictionary.

- Issue #11113: add a new "html5" dictionary containing the named character
  references defined by the HTML5 standard and the equivalent Unicode
  character(s) to the html.entities module.

- Issue #15114: the strict mode of HTMLParser and the HTMLParseError exception
  are deprecated now that the parser is able to parse invalid markup.

- Issue #3665: \u and \U escapes are now supported in unicode regular
  expressions.  Patch by Serhiy Storchaka.

- Issue #15153: Added inspect.getgeneratorlocals to simplify white box
  testing of generator state updates

- Issue #13062: Added inspect.getclosurevars to simplify testing stateful
  closures

- Issue #11024: Fixes and additional tests for Time2Internaldate.

- Issue #14626: Large refactoring of functions / parameters in the os module.
  Many functions now support "dir_fd" and "follow_symlinks" parameters;
  some also support accepting an open file descriptor in place of of a path
  string.  Added os.support_* collections as LBYL helpers.  Removed many
  functions only previously seen in 3.3 alpha releases (often starting with
  "f" or "l", or ending with "at").  Originally suggested by Serhiy Storchaka;
  implemented by Larry Hastings.

- Issue #15008: Implement PEP 362 "Signature Objects".
  Patch by Yury Selivanov.

- Issue: #15138: base64.urlsafe_{en,de}code() are now 3-4x faster.

- Issue #444582: Add shutil.which, for finding programs on the system path.
  Original patch by Erik Demaine, with later iterations by Jan Killian
  and Brian Curtin.

- Issue #14837: SSL errors now have ``library`` and ``reason`` attributes
  describing precisely what happened and in which OpenSSL submodule.  The
  str() of a SSLError is also enhanced accordingly.

- Issue #9527: datetime.astimezone() method will now supply a class
  timezone instance corresponding to the system local timezone when
  called with no arguments.

- Issue #14653: email.utils.mktime_tz() no longer relies on system
  mktime() when timezone offest is supplied.

- Issue #14684: zlib.compressobj() and zlib.decompressobj() now support the use
  of predefined compression dictionaries. Original patch by Sam Rushing.

- Fix GzipFile's handling of filenames given as bytes objects.

- Issue #14772: Return destination values from some shutil functions.

- Issue #15064: Implement context manager protocol for multiprocessing types

- Issue #15101: Make pool finalizer avoid joining current thread.

- Issue #14657: The frozen instance of importlib used for bootstrap is now
  also the module imported as importlib._bootstrap.

- Issue #14055: Add __sizeof__ support to _elementtree.

- Issue #15054: A bug in tokenize.tokenize that caused string literals
  with 'b' prefixes to be incorrectly tokenized has been fixed.
  Patch by Serhiy Storchaka.

- Issue #15006: Allow equality comparison between naive and aware
  time or datetime objects.

- Issue #14982: Document that pkgutil's iteration functions require the
  non-standard iter_modules() method to be defined by an importer (something
  the importlib importers do not define).

- Issue #15036: Mailbox no longer throws an error if a flush is done
  between operations when removing or changing multiple items in mbox,
  MMDF, or Babyl mailboxes.

- Issue #14059: Implement multiprocessing.Barrier.

- Issue #15061: The inappropriately named hmac.secure_compare has been
  renamed to hmac.compare_digest, restricted to operating on bytes inputs
  only and had its documentation updated to more accurately reflect both its
  intent and its limitations

- Issue #13841: Make child processes exit using sys.exit() on Windows.

- Issue #14936: curses_panel was converted to PEP 3121 and PEP 384 API.
  Patch by Robin Schreiber.

- Issue #1667546: On platforms supporting tm_zone and tm_gmtoff fields
  in struct tm, time.struct_time objects returned by time.gmtime(),
  time.localtime() and time.strptime() functions now have tm_zone and
  tm_gmtoff attributes.  Original patch by Paul Boddie.

- Rename adjusted attribute to adjustable in time.get_clock_info() result.

- Issue #3518: Remove references to non-existent BaseManager.from_address()
  method.

- Issue #13857: Added textwrap.indent() function (initial patch by Ezra
  Berch)

- Issue #2736: Added datetime.timestamp() method.

- Issue #13854: Make multiprocessing properly handle non-integer
  non-string argument to SystemExit.

- Issue #12157: Make pool.map() empty iterables correctly.  Initial
  patch by mouad.

- Issue #11823: disassembly now shows argument counts on calls with keyword args.

- Issue #14711: os.stat_float_times() has been deprecated.

- LZMAFile now accepts the modes "rb"/"wb"/"ab" as synonyms of "r"/"w"/"a".

- The bz2 and lzma modules now each contain an open() function, allowing
  compressed files to readily be opened in text mode as well as binary mode.

- BZ2File.__init__() and LZMAFile.__init__() now accept a file object as their
  first argument, rather than requiring a separate "fileobj" argument.

- gzip.open() now accepts file objects as well as filenames.

- Issue #14992: os.makedirs(path, exist_ok=True) would raise an OSError
  when the path existed and had the S_ISGID mode bit set when it was
  not explicitly asked for.  This is no longer an exception as mkdir
  cannot control if the OS sets that bit for it or not.

- Issue #14989: Make the CGI enable option to http.server available via command
  line.

- Issue #14987: Add a missing import statement to inspect.

- Issue #1079: email.header.decode_header now correctly parses all the examples
  in RFC2047.  There is a necessary visible behavior change: the leading and/or
  trailing whitespace on ASCII parts is now preserved.

- Issue #14969: Better handling of exception chaining in contextlib.ExitStack

- Issue #14962: Update text coloring in IDLE shell window after changing
  options.  Patch by Roger Serwy.

- Issue #14963: Convert contextlib.ExitStack.__exit__ to use an iterative
  algorithm (Patch by Alon Horev)

- Issue #14785: Add sys._debugmallocstats() to help debug low-level memory
  allocation issues

- Issue #14443: Ensure that .py files are byte-compiled with the correct Python
  executable within bdist_rpm even on older versions of RPM

C-API
-----

- Issue #13783: Inadvertent additions to the public C API in the PEP 380
  implementation have either been removed or marked as private interfaces.

Extension Modules
-----------------

- Issue #15000: Support the "unique" x32 architecture in _posixsubprocess.c.

Documentation
-------------

- Issue #15081: Document PyState_FindModule.
  Patch by Robin Schreiber.

- Issue #14814: Added first draft of ipaddress module API reference

Tests
-----

- Issue #14769: test_capi now has SkipitemTest, which cleverly checks
  for "parity" between PyArg_ParseTuple() and the Python/getargs.c static
  function skipitem() for all possible "format units".

- test_nntplib now tolerates being run from behind NNTP gateways that add
  "X-Antivirus" headers to articles

- Issue #15043: test_gdb is now skipped entirely if gdb security settings
  block loading of the gdb hooks

- Issue #14963: Add test cases for exception handling behaviour
  in contextlib.ExitStack (Initial patch by Alon Horev)

Build
-----

- Issue #13590: Improve support for OS X Xcode 4:
    * Try to avoid building Python or extension modules with problematic
      llvm-gcc compiler.
    * Since Xcode 4 removes ppc support, extension module builds now
      check for ppc compiler support and automatically remove ppc and
      ppc64 archs when not available.
    * Since Xcode 4 no longer install SDKs in default locations,
      extension module builds now revert to using installed headers
      and libs if the SDK used to build the interpreter is not
      available.
    * Update ./configure to use better defaults for universal builds;
      in particular, --enable-universalsdk=yes uses the Xcode default
      SDK and --with-universal-archs now defaults to "intel" if ppc
      not available.

- Issue #14225: Fix Unicode support for curses (#12567) on OS X

- Issue #14928: Fix importlib bootstrap issues by using a custom executable
  (Modules/_freeze_importlib) to build Python/importlib.h.


What's New in Python 3.3.0 Alpha 4?
===================================

*Release date: 31-May-2012*

Core and Builtins
-----------------

- Issue #14835: Make plistlib output empty arrays & dicts like OS X.
  Patch by Sidney San Martín.

- Issue #14744: Use the new _PyUnicodeWriter internal API to speed up
  str%args and str.format(args).

- Issue #14930: Make memoryview objects weakrefable.

- Issue #14775: Fix a potential quadratic dict build-up due to the garbage
  collector repeatedly trying to untrack dicts.

- Issue #14857: fix regression in references to PEP 3135 implicit __class__
  closure variable (Reopens issue #12370)

- Issue #14712 (PEP 405): Virtual environments. Implemented by Vinay Sajip.

- Issue #14660 (PEP 420): Namespace packages. Implemented by Eric Smith.

- Issue #14494: Fix __future__.py and its documentation to note that
  absolute imports are the default behavior in 3.0 instead of 2.7.
  Patch by Sven Marnach.

- Issue #9260: A finer-grained import lock.  Most of the import sequence
  now uses per-module locks rather than the global import lock, eliminating
  well-known issues with threads and imports.

- Issue #14624: UTF-16 decoding is now 3x to 4x faster on various inputs.
  Patch by Serhiy Storchaka.

- asdl_seq and asdl_int_seq are now Py_ssize_t sized.

- Issue #14133 (PEP 415): Implement suppression of __context__ display with an
  attribute on BaseException. This replaces the original mechanism of PEP 409.

- Issue #14417: Mutating a dict during lookup now restarts the lookup instead
  of raising a RuntimeError (undoes issue #14205).

- Issue #14738: Speed-up UTF-8 decoding on non-ASCII data.  Patch by Serhiy
  Storchaka.

- Issue #14700: Fix two broken and undefined-behaviour-inducing overflow checks
  in old-style string formatting.

- Issue #14705: The PyArg_Parse() family of functions now support the 'p' format
  unit, which accepts a "boolean predicate" argument.  It converts any Python
  value into an integer--0 if it is "false", and 1 otherwise.

Library
-------

- Issue #14690: Use monotonic clock instead of system clock in the sched,
  subprocess and trace modules.

- Issue #14958: Change IDLE systax highlighting to recognize all string and
  byte literals supported in Python 3.3.

- Issue #10997: Prevent a duplicate entry in IDLE's "Recent Files" menu.

- Issue #14443: Tell rpmbuild to use the correct version of Python in
  bdist_rpm. Initial patch by Ross Lagerwall.

- Issue #14929: Stop Idle 3.x from closing on Unicode decode errors when
  grepping. Patch by Roger Serwy.

- Issue #12515: email now registers a defect if it gets to EOF while parsing
  a MIME part without seeing the closing MIME boundary.

- Issue #12510: Attempting to get invalid tooltip no longer closes Idle.
  Other tooltipss have been corrected or improved and the number of tests
  has been tripled. Original patch by Roger Serwy.

- Issue #1672568: email now always decodes base64 payloads, adding padding and
  ignoring non-base64-alphabet characters if needed, and registering defects
  for any such problems.

- Issue #14925: email now registers a defect when the parser decides that there
  is a missing header/body separator line.  MalformedHeaderDefect, which the
  existing code would never actually generate, is deprecated.

- Issue #10365: File open dialog now works instead of crashing even when
  the parent window is closed before the dialog. Patch by Roger Serwy.

- Issue #8739: Updated smtpd to support RFC 5321, and added support for the
  RFC 1870 SIZE extension.

- Issue #665194: Added a localtime function to email.utils to provide an
  aware local datetime for use in setting Date headers.

- Issue #12586: Added new provisional policies that implement convenient
  unicode support for email headers.  See What's New for details.

- Issue #14731: Refactored email Policy framework to support full backward
  compatibility with Python 3.2 by default yet allow for the introduction of
  new features through new policies.  Note that Policy.must_be_7bit is renamed
  to cte_type.

- Issue #14876: Use user-selected font for highlight configuration.

- Issue #14920: Fix the help(urllib.parse) failure on locale C on terminals.
  Have ascii characters in help.

- Issue #14548: Make multiprocessing finalizers check pid before
  running to cope with possibility of gc running just after fork.

- Issue #14863: Update the documentation of os.fdopen() to reflect the
  fact that it's only a thin wrapper around open() anymore.

- Issue #14036: Add an additional check to validate that port in urlparse does
  not go in illegal range and returns None.

- Issue #14862: Add missing names to os.__all__

- Issue #14875: Use float('inf') instead of float('1e66666') in the json module.

- Issue #13585: Added contextlib.ExitStack

- PEP 3144, Issue #14814: Added the ipaddress module

- Issue #14426: Correct the Date format in Expires attribute of Set-Cookie
  Header in Cookie.py.

- Issue #14588: The types module now provide new_class() and prepare_class()
  functions to support PEP 3115 compliant dynamic class creation. Patch by
  Daniel Urban and Nick Coghlan.

- Issue #13152: Allow to specify a custom tabsize for expanding tabs in
  textwrap. Patch by John Feuerstein.

- Issue #14721: Send the correct 'Content-length: 0' header when the body is an
  empty string ''. Initial Patch contributed by Arve Knudsen.

- Issue #14072: Fix parsing of 'tel' URIs in urlparse by making the check for
  ports stricter.

- Issue #9374: Generic parsing of query and fragment portions of url for any
  scheme. Supported both by RFC3986 and RFC2396.

- Issue #14798: Fix the functions in pyclbr to raise an ImportError
  when the first part of a dotted name is not a package. Patch by
  Xavier de Gaye.

- Issue #12098: multiprocessing on Windows now starts child processes
  using the same sys.flags as the current process.  Initial patch by
  Sergey Mezentsev.

- Issue #13031: Small speed-up for tarfile when unzipping tarfiles.
  Patch by Justin Peel.

- Issue #14780: urllib.request.urlopen() now has a ``cadefault`` argument
  to use the default certificate store.  Initial patch by James Oakley.

- Issue #14829: Fix bisect and range() indexing with large indices
  (>= 2 ** 32) under 64-bit Windows.

- Issue #14732: The _csv module now uses PEP 3121 module initialization.
  Patch by Robin Schreiber.

- Issue #14809: Add HTTP status codes introduced by RFC 6585 to http.server
  and http.client. Patch by EungJun Yi.

- Issue #14777: tkinter may return undecoded UTF-8 bytes as a string when
  accessing the Tk clipboard.  Modify clipboad_get() to first request type
  UTF8_STRING when no specific type is requested in an X11 windowing
  environment, falling back to the current default type STRING if that fails.
  Original patch by Thomas Kluyver.

- Issue #14773: Fix os.fwalk() failing on dangling symlinks.

- Issue #12541: Be lenient with quotes around Realm field of HTTP Basic
  Authentation in urllib2.

- Issue #14807: move undocumented tarfile.filemode() to stat.filemode() and add
  doc entry. Add tarfile.filemode alias with deprecation warning.

- Issue #13815: TarFile.extractfile() now returns io.BufferedReader objects.

- Issue #14532: Add a secure_compare() helper to the hmac module, to mitigate
  timing attacks. Patch by Jon Oberheide.

- Add importlib.util.resolve_name().

- Issue #14366: Support lzma compression in zip files.
  Patch by Serhiy Storchaka.

- Issue #13959: Introduce importlib.find_loader() and document
  imp.find_module/load_module as deprecated.

- Issue #14082: shutil.copy2() now copies extended attributes, if possible.
  Patch by Hynek Schlawack.

- Issue #13959: Make importlib.abc.FileLoader.load_module()/get_filename() and
  importlib.machinery.ExtensionFileLoader.load_module() have their single
  argument be optional. Allows for the replacement (and thus deprecation) of
  imp.load_source()/load_package()/load_compiled().

- Issue #13959: imp.get_suffixes() has been deprecated in favour of the new
  attributes on importlib.machinery: SOURCE_SUFFIXES, DEBUG_BYTECODE_SUFFIXES,
  OPTIMIZED_BYTECODE_SUFFIXES, BYTECODE_SUFFIXES, and EXTENSION_SUFFIXES. This
  led to an indirect deprecation of inspect.getmoduleinfo().

- Issue #14662: Prevent shutil failures on OS X when destination does not
  support chflag operations.  Patch by Hynek Schlawack.

- Issue #14157: Fix time.strptime failing without a year on February 29th.
  Patch by Hynek Schlawack.

- Issue #14753: Make multiprocessing's handling of negative timeouts
  the same as it was in Python 3.2.

- Issue #14583: Fix importlib bug when a package's __init__.py would first
  import one of its modules then raise an error.

- Issue #14741: Fix missing support for Ellipsis ('...') in parser module.

- Issue #14697: Fix missing support for set displays and set comprehensions in
  parser module.

- Issue #14701: Fix missing support for 'raise ... from' in parser module.

- Add support for timeouts to the acquire() methods of
  multiprocessing's lock/semaphore/condition proxies.

- Issue #13989: Add support for text mode to gzip.open().

- Issue #14127: The os.stat() result object now provides three additional
  fields: st_ctime_ns, st_mtime_ns, and st_atime_ns, providing those times as an
  integer with nanosecond resolution.  The functions os.utime(), os.lutimes(),
  and os.futimes() now accept a new parameter, ns, which accepts mtime and atime
  as integers with nanosecond resolution.

- Issue #14127 and #10148: shutil.copystat now preserves exact mtime and atime
  on filesystems providing nanosecond resolution.

Tools/Demos
-----------

- Issue #14695: Bring Tools/parser/unparse.py support up to date with
  the Python 3.3 Grammar.

Build
-----

- Issue #14472: Update .gitignore. Patch by Matej Cepl.

- Upgrade Windows library versions: bzip 1.0.6, OpenSSL 1.0.1c.

- Issue #14693: Under non-Windows platforms, hashlib's fallback modules are
  always compiled, even if OpenSSL is present at build time.

- Issue #13210: Windows build now uses VS2010, ported from VS2008.

Documentation
-------------

- Issue #14588: The language reference now accurately documents the Python 3
  class definition process. Patch by Nick Coghlan.

- Issue #14943: Correct a default argument value for winreg.OpenKey
  and correctly list the argument names in the function's explanation.


What's New in Python 3.3.0 Alpha 3?
===================================

*Release date: 01-May-2012*

Core and Builtins
-----------------

- Issue #14699: Fix calling the classmethod descriptor directly.

- Issue #14433: Prevent msvcrt crash in interactive prompt when stdin is closed.

- Issue #14521: Make result of float('nan') and float('-nan') more consistent
  across platforms.

- Issue #14646: __import__() sets __loader__ if the loader did not.

- Issue #14605: No longer have implicit entries in sys.meta_path. If
  sys.meta_path is found to be empty, raise ImportWarning.

- Issue #14605: No longer have implicit entries in sys.path_hooks. If
  sys.path_hooks is found to be empty, a warning will be raised. None is now
  inserted into sys.path_importer_cache if no finder was discovered. This also
  means imp.NullImporter is no longer implicitly used.

- Issue #13903: Implement PEP 412. Individual dictionary instances can now share
  their keys with other dictionaries. Classes take advantage of this to share
  their instance dictionary keys for improved memory and performance.

- Issue #11603 (again): Setting __repr__ to __str__ now raises a RuntimeError
  when repr() or str() is called on such an object.

- Issue #14658: Fix binding a special method to a builtin implementation of a
  special method with a different name.

- Issue #14630: Fix a memory access bug for instances of a subclass of int
  with value 0.

- Issue #14339: Speed improvements to bin, oct and hex functions.  Patch by
  Serhiy Storchaka.

- Issue #14098: New functions PyErr_GetExcInfo and PyErr_SetExcInfo.
  Patch by Stefan Behnel.

- Issue #14385: It is now possible to use a custom type for the __builtins__
  namespace, instead of a dict. It can be used for sandboxing for example.
  Raise also a NameError instead of ImportError if __build_class__ name if not
  found in __builtins__.

- Issue #12599: Be more strict in accepting None compared to a false-like
  object for importlib.util.module_for_loader and
  importlib.machinery.PathFinder.

- Issue #14612: Fix jumping around with blocks by setting f_lineno.

- Issue #14592: Attempting a relative import w/o __package__ or __name__ set in
  globals raises a KeyError.

- Issue #14607: Fix keyword-only arguments which started with ``__``.

- Issue #10854: The ImportError raised when an extension module on Windows
  fails to import now uses the new path and name attributes from
  Issue #1559549.

- Issue #13889: Check and (if necessary) set FPU control word before calling
  any of the dtoa.c string <-> float conversion functions, on MSVC builds of
  Python.  This fixes issues when embedding Python in a Delphi app.

- __import__() now matches PEP 328 and documentation by defaulting 'index' to 0
  instead of -1 and removing support for negative values.

- Issue #2377: Make importlib the implementation of __import__().

- Issue #1559549: ImportError now has 'name' and 'path' attributes that are set
  using keyword arguments to its constructor. They are currently not set by
  import as they are meant for use by importlib.

- Issue #14474: Save and restore exception state in thread.start_new_thread()
  while writing error message if the thread leaves a unhandled exception.

- Issue #13019: Fix potential reference leaks in bytearray.extend().  Patch
  by Suman Saha.

Library
-------

- Issue #14768: os.path.expanduser('~/a') doesn't works correctly when HOME is '/'.

- Issue #14371: Support bzip2 in zipfile module.  Patch by Serhiy Storchaka.

- Issue #13183: Fix pdb skipping frames after hitting a breakpoint and running
  step.  Patch by Xavier de Gaye.

- Issue #14696: Fix parser module to understand 'nonlocal' declarations.

- Issue #10941: Fix imaplib.Internaldate2tuple to produce correct result near
  the DST transition.  Patch by Joe Peterson.

- Issue #9154: Fix parser module to understand function annotations.

- Issue #6085: In http.server.py SimpleHTTPServer.address_string returns the
  client ip address instead client hostname. Patch by Charles-François Natali.

- Issue #14309: Deprecate time.clock(), use time.perf_counter() or
  time.process_time() instead.

- Issue #14428: Implement the PEP 418. Add time.get_clock_info(),
  time.perf_counter() and time.process_time() functions, and rename
  time.steady() to time.monotonic().

- Issue #14646: importlib.util.module_for_loader() now sets __loader__ and
  __package__ (when possible).

- Issue #14664: It is now possible to use @unittest.skip{If,Unless} on a
  test class that doesn't inherit from TestCase (i.e. a mixin).

- Issue #4892: multiprocessing Connections can now be transferred over
  multiprocessing Connections.  Patch by Richard Oudkerk (sbt).

- Issue #14160: TarFile.extractfile() failed to resolve symbolic links when
  the links were not located in an archive subdirectory.

- Issue #14638: pydoc now treats non-string __name__ values as if they
  were missing, instead of raising an error.

- Issue #13684: Fix httplib tunnel issue of infinite loops for certain sites
  which send EOF without trailing \r\n.

- Issue #14605: Add importlib.abc.FileLoader, importlib.machinery.(FileFinder,
  SourceFileLoader, SourcelessFileLoader, ExtensionFileLoader).

- Issue #13959: imp.cache_from_source()/source_from_cache() now follow
  os.path.join()/split() semantics for path manipulation instead of its prior,
  custom semantics of caring the right-most path separator forward in path
  joining.

- Issue #2193: Allow ":" character in Cookie NAME values.

- Issue #14629: tokenizer.detect_encoding will specify the filename in the
  SyntaxError exception if found at readline.__self__.name.

- Issue #14629: Raise SyntaxError in tokenizer.detect_encoding if the
  first two lines have non-UTF-8 characters without an encoding declaration.

- Issue #14308: Fix an exception when a "dummy" thread is in the threading
  module's active list after a fork().

- Issue #11750: The Windows API functions scattered in the _subprocess and
  _multiprocessing.win32 modules now live in a single module "_winapi".
  Patch by sbt.

- Issue #14087: multiprocessing: add Condition.wait_for(). Patch by sbt.

- Issue #14538: HTMLParser can now parse correctly start tags that contain
  a bare '/'.

- Issue #14452: SysLogHandler no longer inserts a UTF-8 BOM into the message.

- Issue #14386: Expose the dict_proxy internal type as types.MappingProxyType.

- Issue #13959: Make imp.reload() always use a module's __loader__ to perform
  the reload.

- Issue #13959: Add imp.py and rename the built-in module to _imp, allowing for
  re-implementing parts of the module in pure Python.

- Issue #13496: Fix potential overflow in bisect.bisect algorithm when applied
  to a collection of size > sys.maxsize / 2.

- Have importlib take advantage of ImportError's new 'name' and 'path'
  attributes.

- Issue #14399: zipfile now recognizes that the archive has been modified even
  if only the comment is changed.  In addition, the TypeError that results from
  trying to set a non-binary value as a comment is now now raised at the time
  the comment is set rather than at the time the zipfile is written.

- trace.CoverageResults.is_ignored_filename() now ignores any name that starts
  with "<" and ends with ">" instead of special-casing "<string>" and
  "<doctest ".

- Issue #12537: The mailbox module no longer depends on knowledge of internal
  implementation details of the email package Message object.

- Issue #7978: socketserver now restarts the select() call when EINTR is
  returned.  This avoids crashing the server loop when a signal is received.
  Patch by Jerzy Kozera.

- Issue #14522: Avoid duplicating socket handles in multiprocessing.connection.
  Patch by sbt.

- Don't Py_DECREF NULL variable in io.IncrementalNewlineDecoder.

- Issue #8515: Set __file__ when run file in IDLE.
  Initial patch by Bruce Frederiksen.

- Issue #14496: Fix wrong name in idlelib/tabbedpages.py.
  Patch by Popa Claudiu.

- Issue #3033: Add displayof parameter to tkinter font. Patch by Guilherme Polo.

- Issue #14482: Raise a ValueError, not a NameError, when trying to create
  a multiprocessing Client or Listener with an AF_UNIX type address under
  Windows.  Patch by Popa Claudiu.

- Issue #802310: Generate always unique tkinter font names if not directly passed.

- Issue #14151: Raise a ValueError, not a NameError, when trying to create
  a multiprocessing Client or Listener with an AF_PIPE type address under
  non-Windows platforms.  Patch by Popa Claudiu.

- Issue #14493: Use gvfs-open or xdg-open in webbrowser.

Build
-----

- "make touch" will now touch generated files that are checked into Mercurial,
  after a "hg update" which failed to bring the timestamps into the right order.

Tests
-----

- Issue #14026: In test_cmd_line_script, check that sys.argv is populated
  correctly for the various invocation approaches (Patch by Jason Yeo)

- Issue #14032: Fix incorrect variable name in test_cmd_line_script debugging
  message (Patch by Jason Yeo)

- Issue #14589: Update certificate chain for sha256.tbs-internet.com, fixing
  a test failure in test_ssl.

- Issue #14355: Regrtest now supports the standard unittest test loading, and
  will use it if a test file contains no `test_main` method.

Tools / Demos
-------------

- Issue #3561: The Windows installer now has an option, off by default, for
  placing the Python installation into the system "Path" environment variable.

- Issue #13165: stringbench is now available in the Tools/stringbench folder.
  It used to live in its own SVN project.


What's New in Python 3.3.0 Alpha 2?
===================================

*Release date: 01-Apr-2012*

Core and Builtins
-----------------

- Issue #1683368: object.__new__ and object.__init__ raise a TypeError if they
  are passed arguments and their complementary method is not overridden.

- Issue #14378: Fix compiling ast.ImportFrom nodes with a "__future__" string as
  the module name that was not interned.

- Issue #14331: Use significantly less stack space when importing modules by
  allocating path buffers on the heap instead of the stack.

- Issue #14334: Prevent in a segfault in type.__getattribute__ when it was not
  passed strings.

- Issue #1469629: Allow cycles through an object's __dict__ slot to be
  collected. (For example if ``x.__dict__ is x``).

- Issue #14205: dict lookup raises a RuntimeError if the dict is modified
  during a lookup.

- Issue #14220: When a generator is delegating to another iterator with the
  yield from syntax, it needs to have its ``gi_running`` flag set to True.

- Issue #14435: Remove dedicated block allocator from floatobject.c and rely
  on the PyObject_Malloc() api like all other objects.

- Issue #14471: Fix a possible buffer overrun in the winreg module.

- Issue #14288: Allow the serialization of builtin iterators

Library
-------

- Issue #14300: Under Windows, sockets created using socket.dup() now allow
  overlapped I/O.  Patch by sbt.

- Issue #13872: socket.detach() now marks the socket closed (as mirrored
  in the socket repr()).  Patch by Matt Joiner.

- Issue #14406: Fix a race condition when using ``concurrent.futures.wait(
  return_when=ALL_COMPLETED)``.  Patch by Matt Joiner.

- Issue #5136: deprecate old, unused functions from tkinter.

- Issue #14409: IDLE now properly executes commands in the Shell window
  when it cannot read the normal config files on startup and
  has to use the built-in default key bindings.
  There was previously a bug in one of the defaults.

- Issue #14416: syslog now defines the LOG_ODELAY and LOG_AUTHPRIV constants
  if they are defined in <syslog.h>.

- IDLE can be launched as python -m idlelib

- Issue #14295: Add unittest.mock

- Issue #7652: Add --with-system-libmpdec option to configure for linking
  the _decimal module against an installed libmpdec.

- Issue #14380: MIMEText now defaults to utf-8 when passed non-ASCII unicode
  with no charset specified.

- Issue #10340: asyncore - properly handle EINVAL in dispatcher constructor on
  OSX; avoid to call handle_connect in case of a disconnected socket which
  was not meant to connect.

- Issue #14204: The ssl module now has support for the Next Protocol
  Negotiation extension, if available in the underlying OpenSSL library.
  Patch by Colin Marc.

- Issue #3035: Unused functions from tkinter are marked as pending deprecated.

- Issue #12757: Fix the skipping of doctests when python is run with -OO so
  that it works in unittest's verbose mode as well as non-verbose mode.

- Issue #7652: Integrate the decimal floating point libmpdec library to speed
  up the decimal module. Performance gains of the new C implementation are
  between 10x and 100x, depending on the application.

- Issue #3573: IDLE hangs when passing invalid command line args
  (directory(ies) instead of file(s)) (Patch by Guilherme Polo)

- Issue #14269: SMTPD now conforms to the RFC and requires a HELO command
  before MAIL, RCPT, or DATA.

- Issue #13694: asynchronous connect in asyncore.dispatcher does not set addr
  attribute.

- Issue #14344: fixed the repr of email.policy objects.

- Issue #11686: Added missing entries to email package __all__ lists
  (mostly the new Bytes classes).

- Issue #14335: multiprocessing's custom Pickler subclass now inherits from
  the C-accelerated implementation.  Patch by sbt.

- Issue #10484: Fix the CGIHTTPServer's PATH_INFO handling problem.

- Issue #11199: Fix the with urllib which hangs on particular ftp urls.

- Improve the memory utilization and speed of functools.lru_cache.

- Issue #14222: Use the new time.steady() function instead of time.time() for
  timeout in queue and threading modules to not be affected of system time
  update.

- Issue #13248: Remove lib2to3.pytree.Base.get_prefix/set_prefix.

- Issue #14234: CVE-2012-0876: Randomize hashes of xml attributes in the hash
  table internal to the pyexpat module's copy of the expat library to avoid a
  denial of service due to hash collisions.  Patch by David Malcolm with some
  modifications by the expat project.

- Issue #14200: Idle shell crash on printing non-BMP unicode character.

- Issue #12818: format address no longer needlessly \ escapes ()s in names when
  the name ends up being quoted.

- Issue #14062: BytesGenerator now correctly folds Header objects,
  including using linesep when folding.

- Issue #13839: When invoked on the command-line, the pstats module now
  accepts several filenames of profile stat files and merges them all.
  Patch by Matt Joiner.

- Issue #14291: Email now defaults to utf-8 for non-ASCII unicode headers
  instead of raising an error.  This fixes a regression relative to 2.7.

- Issue #989712: Support using Tk without a mainloop.

- Issue #5219: Prevent event handler cascade in IDLE.

- Issue #3835: Refuse to use unthreaded Tcl in threaded Python.

- Issue #2843: Add new Tk API to Tkinter.

- Issue #14184: Increase the default stack size for secondary threads on
  Mac OS X to avoid interpreter crashes when using threads on 10.7.

- Issue #14180: datetime.date.fromtimestamp(),
  datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp()
  now raise an OSError instead of ValueError if localtime() or gmtime() failed.

- Issue #14180: time.ctime(), gmtime(), time.localtime(),
  datetime.date.fromtimestamp(), datetime.datetime.fromtimestamp() and
  datetime.datetime.utcfromtimestamp() now raises an OverflowError, instead of
  a ValueError, if the timestamp does not fit in time_t.

- Issue #14180: datetime.datetime.fromtimestamp() and
  datetime.datetime.utcfromtimestamp() now round microseconds towards zero
  instead of rounding to nearest with ties going away from zero.

- Issue #10543: Fix unittest test discovery with Jython bytecode files.

- Issue #1178863: Separate initialisation from setting when initializing
  Tkinter.Variables; harmonize exceptions to ValueError; only delete variables
  that have not been deleted; assert that variable names are strings.

- Issue #14104: Implement time.monotonic() on Mac OS X, patch written by
  Nicholas Riley.

- Issue #13394: the aifc module now uses warnings.warn() to signal warnings.

- Issue #14252: Fix subprocess.Popen.terminate() to not raise an error under
  Windows when the child process has already exited.

- Issue #14223: curses.addch() is no more limited to the range 0-255 when the
  Python curses is not linked to libncursesw. It was a regression introduced
  in Python 3.3a1.

- Issue #14168: Check for presence of Element._attrs in minidom before
  accessing it.

- Issue #12328: Fix multiprocessing's use of overlapped I/O on Windows.
  Also, add a multiprocessing.connection.wait(rlist, timeout=None) function
  for polling multiple objects at once.  Patch by sbt.

- Issue #14007: Accept incomplete TreeBuilder objects (missing start, end,
  data or close method) for the Python implementation as well.
  Drop the no-op TreeBuilder().xml() method from the C implementation.

- Issue #14210: pdb now has tab-completion not only for command names, but
  also for their arguments, wherever possible.

- Issue #14310: Sockets can now be with other processes on Windows using
  the api socket.socket.share() and socket.fromshare().

- Issue #10576: The gc module now has a 'callbacks' member that will get
  called when garbage collection takes place.

Build
-----

- Issue #14557: Fix extensions build on HP-UX. Patch by Adi Roiban.

- Issue #14387: Do not include accu.h from Python.h.

- Issue #14359: Only use O_CLOEXEC in _posixmodule.c if it is defined.
  Based on patch from Hervé Coatanhay.

- Issue #14321: Do not run pgen during the build if files are up to date.

Documentation
-------------

- Issue #14034: added the argparse tutorial.

- Issue #14324: Fix configure tests for cross builds.

- Issue #14327: Call AC_CANONICAL_HOST in configure.ac and check in
  config.{guess,sub}. Don't use uname calls for cross builds.

Extension Modules
-----------------

- Issue #9041: An issue in ctypes.c_longdouble, ctypes.c_double, and
  ctypes.c_float that caused an incorrect exception to be returned in the
  case of overflow has been fixed.

- Issue #14212: The re module didn't retain a reference to buffers it was
  scanning, resulting in segfaults.

- Issue #14259: The finditer() method of re objects did not take any
  keyword arguments, contrary to the documentation.

- Issue #10142: Support for SEEK_HOLE/SEEK_DATA (for example, under ZFS).

Tests
-----

- Issue #14442: Add missing errno import in test_smtplib.

- Issue #8315: (partial fix) python -m unittest test.test_email now works.


What's New in Python 3.3.0 Alpha 1?
===================================

*Release date: 05-Mar-2012*

Core and Builtins
-----------------

- Issue #14172: Fix reference leak when marshalling a buffer-like object
  (other than a bytes object).

- Issue #13521: dict.setdefault() now does only one lookup for the given key,
  making it "atomic" for many purposes.  Patch by Filip Gruszczyński.

- PEP 409, Issue #6210: "raise X from None" is now supported as a means of
  suppressing the display of the chained exception context. The chained
  context still remains available as the __context__ attribute.

- Issue #10181: New memoryview implementation fixes multiple ownership
  and lifetime issues of dynamically allocated Py_buffer members (#9990)
  as well as crashes (#8305, #7433). Many new features have been added
  (See whatsnew/3.3), and the documentation has been updated extensively.
  The ndarray test object from _testbuffer.c implements all aspects of
  PEP-3118, so further development towards the complete implementation
  of the PEP can proceed in a test-driven manner.

  Thanks to Nick Coghlan, Antoine Pitrou and Pauli Virtanen for review
  and many ideas.

- Issue #12834: Fix incorrect results of memoryview.tobytes() for
  non-contiguous arrays.

- Issue #5231: Introduce memoryview.cast() method that allows changing
  format and shape without making a copy of the underlying memory.

- Issue #14084: Fix a file descriptor leak when importing a module with a
  bad encoding.

- Upgrade Unicode data to Unicode 6.1.

- Issue #14040: Remove rarely used file name suffixes for C extensions
  (under POSIX mainly).

- Issue #14051: Allow arbitrary attributes to be set of classmethod and
  staticmethod.

- Issue #13703: oCERT-2011-003: Randomize hashes of str and bytes to protect
  against denial of service attacks due to hash collisions within the dict and
  set types.  Patch by David Malcolm, based on work by Victor Stinner.

- Issue #13020: Fix a reference leak when allocating a structsequence object
  fails.  Patch by Suman Saha.

- Issue #13908: Ready types returned from PyType_FromSpec.

- Issue #11235: Fix OverflowError when trying to import a source file whose
  modification time doesn't fit in a 32-bit timestamp.

- Issue #12705: A SyntaxError exception is now raised when attempting to
  compile multiple statements as a single interactive statement.

- Fix the builtin module initialization code to store the init function for
  future reinitialization.

- Issue #8052: The posix subprocess module would take a long time closing
  all possible file descriptors in the child process rather than just open
  file descriptors.  It now closes only the open fds if possible for the
  default close_fds=True behavior.

- Issue #13629: Renumber the tokens in token.h so that they match the indexes
  into _PyParser_TokenNames.

- Issue #13752: Add a casefold() method to str.

- Issue #13761: Add a "flush" keyword argument to the print() function,
  used to ensure flushing the output stream.

- Issue #13645: pyc files now contain the size of the corresponding source
  code, to avoid timestamp collisions (especially on filesystems with a low
  timestamp resolution) when checking for freshness of the bytecode.

- PEP 380, Issue #11682: Add "yield from <x>" to support easy delegation to
  subgenerators (initial patch by Greg Ewing, integration into 3.3 by
  Renaud Blanch, Ryan Kelly, Zbigniew Jędrzejewski-Szmek and Nick Coghlan)

- Issue #13748: Raw bytes literals can now be written with the ``rb`` prefix
  as well as ``br``.

- Issue #12736: Use full unicode case mappings for upper, lower, and title case.

- Issue #12760: Add a create mode to open(). Patch by David Townshend.

- Issue #13738: Simplify implementation of bytes.lower() and bytes.upper().

- Issue #13577: Built-in methods and functions now have a __qualname__.
  Patch by sbt.

- Issue #6695: Full garbage collection runs now clear the freelist of set
  objects.  Initial patch by Matthias Troffaes.

- Fix OSError.__init__ and OSError.__new__ so that each of them can be
  overriden and take additional arguments (followup to issue #12555).

- Fix the fix for issue #12149: it was incorrect, although it had the side
  effect of appearing to resolve the issue.  Thanks to Mark Shannon for
  noticing.

- Issue #13505: Pickle bytes objects in a way that is compatible with
  Python 2 when using protocols <= 2.

- Issue #11147: Fix an unused argument in _Py_ANNOTATE_MEMORY_ORDER.  (Fix
  given by Campbell Barton).

- Issue #13503: Use a more efficient reduction format for bytearrays with
  pickle protocol >= 3.  The old reduction format is kept with older protocols
  in order to allow unpickling under Python 2.  Patch by Irmen de Jong.

- Issue #7111: Python can now be run without a stdin, stdout or stderr
  stream.  It was already the case with Python 2.  However, the corresponding
  sys module entries are now set to None (instead of an unusable file object).

- Issue #11849: Ensure that free()d memory arenas are really released
  on POSIX systems supporting anonymous memory mappings.  Patch by
  Charles-François Natali.

- Issue #13452: PyUnicode_EncodeDecimal() doesn't support error handlers
  different than "strict" anymore. The caller was unable to compute the
  size of the output buffer: it depends on the error handler.

- PEP 3155 / issue #13448: Qualified name for classes and functions.

- Issue #13436: Fix a bogus error message when an AST object was passed
  an invalid integer value.

- Issue #13411: memoryview objects are now hashable when the underlying
  object is hashable.

- Issue #13338: Handle all enumerations in _Py_ANNOTATE_MEMORY_ORDER
  to allow compiling extension modules with -Wswitch-enum on gcc.
  Initial patch by Floris Bruynooghe.

- Issue #10227: Add an allocation cache for a single slice object.  Patch by
  Stefan Behnel.

- Issue #13393: BufferedReader.read1() now asks the full requested size to
  the raw stream instead of limiting itself to the buffer size.

- Issue #13392: Writing a pyc file should now be atomic under Windows as well.

- Issue #13333: The UTF-7 decoder now accepts lone surrogates (the encoder
  already accepts them).

- Issue #13389: Full garbage collection passes now clear the freelists for
  list and dict objects.  They already cleared other freelists in the
  interpreter.

- Issue #13327: Remove the need for an explicit None as the second argument
  to os.utime, os.lutimes, os.futimes, os.futimens, os.futimesat, in
  order to update to the current time. Also added keyword argument
  handling to os.utimensat in order to remove the need for explicit None.

- Issue #13350: Simplify some C code by replacing most usages of
  PyUnicode_Format by PyUnicode_FromFormat.

- Issue #13342: input() used to ignore sys.stdin's and sys.stdout's unicode
  error handler in interactive mode (when calling into PyOS_Readline()).

- Issue #9896: Add start, stop, and step attributes to range objects.

- Issue #13343: Fix a SystemError when a lambda expression uses a global
  variable in the default value of a keyword-only argument: ``lambda *,
  arg=GLOBAL_NAME: None``

- Issue #12797: Added custom opener parameter to builtin open() and
  FileIO.open().

- Issue #10519: Avoid unnecessary recursive function calls in
  setobject.c.

- Issue #10363: Deallocate global locks in Py_Finalize().

- Issue #13018: Fix reference leaks in error paths in dictobject.c.
  Patch by Suman Saha.

- Issue #13201: Define '==' and '!=' to compare range objects based on
  the sequence of values they define (instead of comparing based on
  object identity).

- Issue #1294232: In a few cases involving metaclass inheritance, the
  interpreter would sometimes invoke the wrong metaclass when building a new
  class object. These cases now behave correctly. Patch by Daniel Urban.

- Issue #12753: Add support for Unicode name aliases and named sequences.
  Both ``unicodedata.lookup()`` and '\N{...}' now resolve aliases,
  and ``unicodedata.lookup()`` resolves named sequences too.

- Issue #12170: The count(), find(), rfind(), index() and rindex() methods
  of bytes and bytearray objects now accept an integer between 0 and 255
  as their first argument.  Patch by Petri Lehtinen.

- Issue #12604: VTRACE macro expanded to no-op in _sre.c to avoid compiler
  warnings. Patch by Josh Triplett and Petri Lehtinen.

- Issue #12281: Rewrite the MBCS codec to handle correctly replace and ignore
  error handlers on all Windows versions. The MBCS codec is now supporting all
  error handlers, instead of only replace to encode and ignore to decode.

- Issue #13188: When called without an explicit traceback argument,
  generator.throw() now gets the traceback from the passed exception's
  ``__traceback__`` attribute.  Patch by Petri Lehtinen.

- Issue #13146: Writing a pyc file is now atomic under POSIX.

- Issue #7833: Extension modules built using distutils on Windows will no
  longer include a "manifest" to prevent them failing at import time in some
  embedded situations.

- PEP 3151 / issue #12555: reworking the OS and IO exception hierarchy.

- Add internal API for static strings (_Py_identifier et al.).

- Issue #13063: the Windows error ERROR_NO_DATA (numbered 232 and described
  as "The pipe is being closed") is now mapped to POSIX errno EPIPE
  (previously EINVAL).

- Issue #12911: Fix memory consumption when calculating the repr() of huge
  tuples or lists.

- PEP 393: flexible string representation. Thanks to Torsten Becker for the
  initial implementation, and Victor Stinner for various bug fixes.

- Issue #14081: The 'sep' and 'maxsplit' parameter to str.split, bytes.split,
  and bytearray.split may now be passed as keyword arguments.

- Issue #13012: The 'keepends' parameter to str.splitlines may now be passed
  as a keyword argument:  "my_string.splitlines(keepends=True)".  The same
  change also applies to bytes.splitlines and bytearray.splitlines.

- Issue #7732: Don't open a directory as a file anymore while importing a
  module. Ignore the direcotry if its name matchs the module name (e.g.
  "__init__.py") and raise a ImportError instead.

- Issue #13021: Missing decref on an error path.  Thanks to Suman Saha for
  finding the bug and providing a patch.

- Issue #12973: Fix overflow checks that relied on undefined behaviour in
  list_repeat (listobject.c) and islice_next (itertoolsmodule.c).  These bugs
  caused test failures with recent versions of Clang.

- Issue #12904: os.utime, os.futimes, os.lutimes, and os.futimesat now write
  atime and mtime with nanosecond precision on modern POSIX platforms.

- Issue #12802: the Windows error ERROR_DIRECTORY (numbered 267) is now
  mapped to POSIX errno ENOTDIR (previously EINVAL).

- Issue #9200: The str.is* methods now work with strings that contain non-BMP
  characters even in narrow Unicode builds.

- Issue #12791: Break reference cycles early when a generator exits with
  an exception.

- Issue #12773: Make __doc__ mutable on user-defined classes.

- Issue #12766: Raise a ValueError when creating a class with a class variable
  that conflicts with a name in __slots__.

- Issue #12266: Fix str.capitalize() to correctly uppercase/lowercase
  titlecased and cased non-letter characters.

- Issue #12732: In narrow unicode builds, allow Unicode identifiers which fall
  outside the BMP.

- Issue #12575: Validate user-generated AST before it is compiled.

- Make type(None), type(Ellipsis), and type(NotImplemented) callable. They
  return the respective singleton instances.

- Forbid summing bytes with sum().

- Verify the types of AST strings and identifiers provided by the user before
  compiling them.

- Issue #12647: The None object now has a __bool__() method that returns False.
  Formerly, bool(None) returned False only because of special case logic
  in PyObject_IsTrue().

- Issue #12579: str.format_map() now raises a ValueError if used on a
  format string that contains positional fields. Initial patch by
  Julian Berman.

- Issue #10271: Allow warnings.showwarning() be any callable.

- Issue #11627: Fix segfault when __new__ on a exception returns a
  non-exception class.

- Issue #12149: Update the method cache after a type's dictionary gets
  cleared by the garbage collector.  This fixes a segfault when an instance
  and its type get caught in a reference cycle, and the instance's
  deallocator calls one of the methods on the type (e.g. when subclassing
  IOBase).  Diagnosis and patch by Davide Rizzo.

- Issue #9611, #9015: FileIO.read() clamps the length to INT_MAX on Windows.

- Issue #9642: Uniformize the tests on the availability of the mbcs codec, add
  a new HAVE_MBCS define.

- Issue #9642: Fix filesystem encoding initialization: use the ANSI code page
  on Windows if the mbcs codec is not available, and fail with a fatal error if
  we cannot get the locale encoding (if nl_langinfo(CODESET) is not available)
  instead of using UTF-8.

- When a generator yields, do not retain the caller's exception state on the
  generator.

- Issue #12475: Prevent generators from leaking their exception state into the
  caller's frame as they return for the last time.

- Issue #12291: You can now load multiple marshalled objects from a stream,
  with other data interleaved between marshalled objects.

- Issue #12356: When required positional or keyword-only arguments are not
  given, produce a informative error message which includes the name(s) of the
  missing arguments.

- Issue #12370: Fix super with no arguments when __class__ is overriden in the
  class body.

- Issue #12084: os.stat on Windows now works properly with relative symbolic
  links when called from any directory.

- Loosen type restrictions on the __dir__ method. __dir__ can now return any
  sequence, which will be converted to a list and sorted by dir().

- Issue #12265: Make error messages produced by passing an invalid set of
  arguments to a function more informative.

- Issue #12225: Still allow Python to build if Python is not in its hg repo or
  mercurial is not installed.

- Issue #1195: my_fgets() now always clears errors before calling fgets(). Fix
  the following case: sys.stdin.read() stopped with CTRL+d (end of file),
  raw_input() interrupted by CTRL+c.

- Issue #12216: Allow unexpected EOF errors to happen on any line of the file.

- Issue #12199: The TryExcept and TryFinally and AST nodes have been unified
  into a Try node.

- Issue #9670: Increase the default stack size for secondary threads on
  Mac OS X and FreeBSD to reduce the chances of a crash instead of a
  "maximum recursion depth" RuntimeError exception.
  (patch by Ronald Oussoren)

- Issue #12106: The use of the multiple-with shorthand syntax is now reflected
  in the AST.

- Issue #12190: Try to use the same filename object when compiling unmarshalling
  a code objects in the same file.

- Issue #12166: Move implementations of dir() specialized for various types into
  the __dir__() methods of those types.

- Issue #5715: In socketserver, close the server socket in the child process.

- Correct lookup of __dir__ on objects. Among other things, this causes errors
  besides AttributeError found on lookup to be propagated.

- Issue #12060: Use sig_atomic_t type and volatile keyword in the signal
  module. Patch written by Charles-François Natali.

- Issue #1746656: Added the if_nameindex, if_indextoname, if_nametoindex
  methods to the socket module.

- Issue #12044: Fixed subprocess.Popen when used as a context manager to
  wait for the process to end when exiting the context to avoid unintentionally
  leaving zombie processes around.

- Issue #1195: Fix input() if it is interrupted by CTRL+d and then CTRL+c,
  clear the end-of-file indicator after CTRL+d.

- Issue #1856: Avoid crashes and lockups when daemon threads run while the
  interpreter is shutting down; instead, these threads are now killed when
  they try to take the GIL.

- Issue #9756: When calling a method descriptor or a slot wrapper descriptor,
  the check of the object type doesn't read the __class__ attribute anymore.
  Fix a crash if a class override its __class__ attribute (e.g. a proxy of the
  str type). Patch written by Andreas Stührk.

- Issue #10517: After fork(), reinitialize the TLS used by the PyGILState_*
  APIs, to avoid a crash with the pthread implementation in RHEL 5.  Patch
  by Charles-François Natali.

- Issue #10914: Initialize correctly the filesystem codec when creating a new
  subinterpreter to fix a bootstrap issue with codecs implemented in Python, as
  the ISO-8859-15 codec.

- Issue #11918: OS/2 and VMS are no more supported because of the lack of
  maintainer.

- Issue #6780: fix starts/endswith error message to mention that tuples are
  accepted too.

- Issue #5057: fix a bug in the peepholer that led to non-portable pyc files
  between narrow and wide builds while optimizing BINARY_SUBSCR on non-BMP
  chars (e.g. "\U00012345"[0]).

- Issue #11845: Fix typo in rangeobject.c that caused a crash in
  compute_slice_indices.  Patch by Daniel Urban.

- Issue #5673: Added a `timeout` keyword argument to subprocess.Popen.wait,
  subprocess.Popen.communicated, subprocess.call, subprocess.check_call, and
  subprocess.check_output.  If the blocking operation takes more than `timeout`
  seconds, the `subprocess.TimeoutExpired` exception is raised.

- Issue #11650: PyOS_StdioReadline() retries fgets() if it was interrupted
  (EINTR), for example if the program is stopped with CTRL+z on Mac OS X. Patch
  written by Charles-Francois Natali.

- Issue #9319: Include the filename in "Non-UTF8 code ..." syntax error.

- Issue #10785: Store the filename as Unicode in the Python parser.

- Issue #11619: _PyImport_LoadDynamicModule() doesn't encode the path to bytes
  on Windows.

- Issue #10998: Remove mentions of -Q, sys.flags.division_warning and
  Py_DivisionWarningFlag left over from Python 2.

- Issue #11244: Remove an unnecessary peepholer check that was preventing
  negative zeros from being constant-folded properly.

- Issue #11395: io.FileIO().write() clamps the data length to 32,767 bytes on
  Windows if the file is a TTY to workaround a Windows bug. The Windows console
  returns an error (12: not enough space error) on writing into stdout if
  stdout mode is binary and the length is greater than 66,000 bytes (or less,
  depending on heap usage).

- Issue #11320: fix bogus memory management in Modules/getpath.c, leading to
  a possible crash when calling Py_SetPath().

- Issue #11432: A bug was introduced in subprocess.Popen on posix systems with
  3.2.0 where the stdout or stderr file descriptor being the same as the stdin
  file descriptor would raise an exception. webbrowser.open would fail. fixed.

- Issue #9856: Change object.__format__ with a non-empty format string
  to be a DeprecationWarning. In 3.2 it was a PendingDeprecationWarning.
  In 3.4 it will be a TypeError.

- Issue #11244: The peephole optimizer is now able to constant-fold
  arbitrarily complex expressions.  This also fixes a 3.2 regression where
  operations involving negative numbers were not constant-folded.

- Issue #11450: Don't truncate hg version info in Py_GetBuildInfo() when
  there are many tags (e.g. when using mq).  Patch by Nadeem Vawda.

- Issue #11335: Fixed a memory leak in list.sort when the key function
  throws an exception.

- Issue #8923: When a string is encoded to UTF-8 in strict mode, the result is
  cached into the object. Examples: str.encode(), str.encode('utf-8'),
  PyUnicode_AsUTF8String() and PyUnicode_AsEncodedString(unicode, "utf-8",
  NULL).

- Issue #10831: PyUnicode_FromFormat() supports %li, %lli and %zi formats.

- Issue #10829: Refactor PyUnicode_FromFormat(), use the same function to parse
  the format string in the 3 steps, fix crashs on invalid format strings.

- Issue #13007: whichdb should recognize gdbm 1.9 magic numbers.

- Issue #11246: Fix PyUnicode_FromFormat("%V") to decode the byte string from
  UTF-8 (with replace error handler) instead of ISO-8859-1 (in strict mode).
  Patch written by Ray Allen.

- Issue #11286: Raise a ValueError from calling PyMemoryView_FromBuffer with
  a buffer struct having a NULL data pointer.

- Issue #11272: On Windows, input() strips '\r' (and not only '\n'), and
  sys.stdin uses universal newline (replace '\r\n' by '\n').

- issue #11828: startswith and endswith don't accept None as slice index.
  Patch by Torsten Becker.

- Issue #10830: Fix PyUnicode_FromFormatV("%c") for non-BMP characters on
  narrow build.

- Issue #11168: Remove filename debug variable from PyEval_EvalFrameEx().
  It encoded the Unicode filename to UTF-8, but the encoding fails on
  undecodable filename (on surrogate characters) which raises an unexpected
  UnicodeEncodeError on recursion limit.

- Issue #11187: Remove bootstrap code (use ASCII) of
  PyUnicode_AsEncodedString(), it was replaced by a better fallback (use the
  locale encoding) in PyUnicode_EncodeFSDefault().

- Check for NULL result in PyType_FromSpec.

- Issue #10516: New copy() and clear() methods for lists and bytearrays.

- Issue #11386: bytearray.pop() now throws IndexError when the bytearray is
  empty, instead of OverflowError.

- Issue #12380: The rjust, ljust and center methods of bytes and bytearray
  now accept a bytearray argument.

Library
-------

- Issue #14195: An issue that caused weakref.WeakSet instances to incorrectly
  return True for a WeakSet instance 'a' in both 'a < a' and 'a > a' has been
  fixed.

- Issue #14166: Pickler objects now have an optional ``dispatch_table``
  attribute which allows to set custom per-pickler reduction functions.
  Patch by sbt.

- Issue #14177: marshal.loads() now raises TypeError when given an unicode
  string.  Patch by Guilherme Gonçalves.

- Issue #13550: Remove the debug machinery from the threading module: remove
  verbose arguments from all threading classes and functions.

- Issue #14159: Fix the len() of weak containers (WeakSet, WeakKeyDictionary,
  WeakValueDictionary) to return a better approximation when some objects
  are dead or dying.  Moreover, the implementation is now O(1) rather than
  O(n).

- Issue #13125: Silence spurious test_lib2to3 output when in non-verbose mode.
  Patch by Mikhail Novikov.

- Issue #11841: Fix comparison bug with 'rc' versions in packaging.version.
  Patch by Filip Gruszczyński.

- Issue #13447: Add a test file to host regression tests for bugs in the
  scripts found in the Tools directory.

- Issue #6884: Fix long-standing bugs with MANIFEST.in parsing in distutils
  on Windows.  Also fixed in packaging.

- Issue #8033: sqlite3: Fix 64-bit integer handling in user functions
  on 32-bit architectures. Initial patch by Philippe Devalkeneer.

- HTMLParser is now able to handle slashes in the start tag.

- Issue #13641: Decoding functions in the base64 module now accept ASCII-only
  unicode strings.  Patch by Catalin Iacob.

- Issue #14043: Speed up importlib's _FileFinder by at least 8x, and add a
  new importlib.invalidate_caches() function.

- Issue #14001: CVE-2012-0845: xmlrpc: Fix an endless loop in
  SimpleXMLRPCServer upon malformed POST request.

- Issue #13961: Move importlib over to using os.replace() for atomic renaming.

- Do away with ambiguous level values (as suggested by PEP 328) in
  importlib.__import__() by raising ValueError when level < 0.

- Issue #2489: pty.spawn could consume 100% cpu when it encountered an EOF.

- Issue #13014: Fix a possible reference leak in SSLSocket.getpeercert().

- Issue #13777: Add PF_SYSTEM sockets on OS X.
  Patch by Michael Goderbauer.

- Issue #13015: Fix a possible reference leak in defaultdict.__repr__.
  Patch by Suman Saha.

- Issue #1326113: distutils' and packaging's build_ext commands option now
  correctly parses multiple values (separated by whitespace or commas) given
  to their --libraries option.

- Issue #10287: nntplib now queries the server's CAPABILITIES first before
  sending MODE READER, and only sends it if not already in READER mode.
  Patch by Hynek Schlawack.

- Issue #13993: HTMLParser is now able to handle broken end tags when
  strict=False.

- Issue #13930: lib2to3 now supports writing converted output files to another
  directory tree as well as copying unchanged files and altering the file
  suffix.

- Issue #9750: Fix sqlite3.Connection.iterdump on tables and fields
  with a name that is a keyword or contains quotes. Patch by Marko
  Kohtala.

- Issue #10287: nntplib now queries the server's CAPABILITIES again after
  authenticating (since the result may change, according to RFC 4643).
  Patch by Hynek Schlawack.

- Issue #13989: Document that GzipFile does not support text mode, and give a
  more helpful error message when opened with an invalid mode string.

- Issue #13590: On OS X 10.7 and 10.6 with Xcode 4.2, building
  Distutils-based packages with C extension modules may fail because
  Apple has removed gcc-4.2, the version used to build python.org
  64-bit/32-bit Pythons.  If the user does not explicitly override
  the default C compiler by setting the CC environment variable,
  Distutils will now attempt to compile extension modules with clang
  if gcc-4.2 is required but not found. Also as a convenience, if
  the user does explicitly set CC, substitute its value as the default
  compiler in the Distutils LDSHARED configuration variable for OS X.
  (Note, the python.org 32-bit-only Pythons use gcc-4.0 and the 10.4u
  SDK, neither of which are available in Xcode 4.  This change does not
  attempt to override settings to support their use with Xcode 4.)

- Issue #13960: HTMLParser is now able to handle broken comments when
  strict=False.

- Issue #13921: Undocument and clean up sqlite3.OptimizedUnicode,
  which is obsolete in Python 3.x. It's now aliased to str for
  backwards compatibility.

- When '' is a path (e.g. in sys.path), make sure __file__ uses the current
  working directory instead of '' in importlib.

- Issue #13609: Add two functions to query the terminal size:
  os.get_terminal_size (low level) and shutil.get_terminal_size (high level).
  Patch by Zbigniew Jędrzejewski-Szmek.

- Issue #13845: On Windows, time.time() now uses GetSystemTimeAsFileTime()
  instead of ftime() to have a resolution of 100 ns instead of 1 ms (the clock
  accuracy is between 0.5 ms and 15 ms).

- Issue #13846: Add time.monotonic(), monotonic clock.

- Issue #8184: multiprocessing: On Windows, don't set SO_REUSEADDR on
  Connection sockets, and set FILE_FLAG_FIRST_PIPE_INSTANCE on named pipes, to
  make sure two listeners can't bind to the same socket/pipe (or any existing
  socket/pipe).

- Issue #9021: Add an introduction to the copy module documentation.

- Issue #6005: Examples in the socket library documentation use sendall, where
  relevant, instead send method.

- Issue #10811: Fix recursive usage of cursors. Instead of crashing,
  raise a ProgrammingError now.

- Issue #10881: Fix test_site failure with OS X framework builds.

- Issue #964437: Make IDLE help window non-modal.
  Patch by Guilherme Polo and Roger Serwy.

- Issue #13734: Add os.fwalk(), a directory walking function yielding file
  descriptors.

- Issue #2945: Make the distutils upload command aware of bdist_rpm products.

- Issue #13712: pysetup create should not convert package_data to extra_files.

- Issue #11805: package_data in setup.cfg should allow more than one value.

- Issue #13933: IDLE auto-complete did not work with some imported
  module, like hashlib.  (Patch by Roger Serwy)

- Issue #13901: Prevent test_distutils failures on OS X with --enable-shared.

- Issue #13676: Handle strings with embedded zeros correctly in sqlite3.

- Issue #13506: Add '' to path for IDLE Shell when started and restarted with Restart Shell.
  Original patches by Marco Scataglini and Roger Serwy.

- Issue #8828: Add new function os.replace(), for cross-platform renaming
  with overwriting.

- Issue #13848: open() and the FileIO constructor now check for NUL
  characters in the file name.  Patch by Hynek Schlawack.

- Issue #13806: The size check in audioop decompression functions was too
  strict and could reject valid compressed data.  Patch by Oleg Plakhotnyuk.

- Issue #13812: When a multiprocessing Process child raises an exception,
  flush stderr after printing the exception traceback.

- Issue #13885: CVE-2011-3389: the _ssl module would always disable the CBC
  IV attack countermeasure.

- Issue #13847: time.localtime() and time.gmtime() now raise an OSError instead
  of ValueError on failure. time.ctime() and time.asctime() now raises an
  OSError if localtime() failed. time.clock() now raises a RuntimeError if the
  processor time used is not available or its value cannot be represented

- Issue #13862: Fix spurious failure in test_zlib due to runtime/compile time
  minor versions not matching.

- Issue #12804: Fix test_socket and test_urllib2net failures when running tests
  on a system without internet access.

- Issue #13772: In os.symlink() under Windows, do not try to guess the link
  target's type (file or directory).  The detection was buggy and made the
  call non-atomic (therefore prone to race conditions).

- Issue #6631: Disallow relative file paths in urllib urlopen methods.

- Issue #13722: Avoid silencing ImportErrors when initializing the codecs
  registry.

- Issue #13781: Fix GzipFile bug that caused an exception to be raised when
  opening for writing using a fileobj returned by os.fdopen().

- Issue #13803: Under Solaris, distutils doesn't include bitness
  in the directory name.

- Issue #10278: Add time.wallclock() function, monotonic clock.

- Issue #13809: Fix regression where bz2 module wouldn't work when threads are
  disabled. Original patch by Amaury Forgeot d'Arc.

- Issue #13589: Fix some serialization primitives in the aifc module.
  Patch by Oleg Plakhotnyuk.

- Issue #13642: Unquote before b64encoding user:password during Basic
  Authentication. Patch contributed by Joonas Kuorilehto.

- Issue #13726: Fix the ambiguous -S flag in regrtest. It is -o/--slow for slow
  tests.

- Issue #12364: Fix a hang in concurrent.futures.ProcessPoolExecutor.
  The hang would occur when retrieving the result of a scheduled future after
  the executor had been shut down.

- Issue #13502: threading: Fix a race condition in Event.wait() that made it
  return False when the event was set and cleared right after.

- Issue #9993: When the source and destination are on different filesystems,
  and the source is a symlink, shutil.move() now recreates a symlink on the
  destination instead of copying the file contents.  Patch by Jonathan Niehof
  and Hynek Schlawack.

- Issue #12926: Fix a bug in tarfile's link extraction.

- Issue #13696: Fix the 302 Relative URL Redirection problem.

- Issue #13636: Weak ciphers are now disabled by default in the ssl module
  (except when SSLv2 is explicitly asked for).

- Issue #12715: Add an optional symlinks argument to shutil functions
  (copyfile, copymode, copystat, copy, copy2).  When that parameter is
  true, symlinks aren't dereferenced and the operation instead acts on the
  symlink itself (or creates one, if relevant).  Patch by Hynek Schlawack.

- Add a flags parameter to select.epoll.

- Issue #12798: Updated the mimetypes documentation.

- Issue #13626: Add support for SSL Diffie-Hellman key exchange, through the
  SSLContext.load_dh_params() method and the ssl.OP_SINGLE_DH_USE option.

- Issue #11006: Don't issue low level warning in subprocess when pipe2() fails.

- Issue #13620: Support for Chrome browser in webbrowser.  Patch contributed
  by Arnaud Calmettes.

- Issue #11829: Fix code execution holes in inspect.getattr_static for
  metaclasses with metaclasses. Patch by Andreas Stührk.

- Issue #12708: Add starmap() and starmap_async() methods (similar to
  itertools.starmap()) to multiprocessing.Pool.  Patch by Hynek Schlawack.

- Issue #1785: Fix inspect and pydoc with misbehaving descriptors.

- Issue #13637: "a2b" functions in the binascii module now accept ASCII-only
  unicode strings.

- Issue #13634: Add support for querying and disabling SSL compression.

- Issue #13627: Add support for SSL Elliptic Curve-based Diffie-Hellman
  key exchange, through the SSLContext.set_ecdh_curve() method and the
  ssl.OP_SINGLE_ECDH_USE option.

- Issue #13635: Add ssl.OP_CIPHER_SERVER_PREFERENCE, so that SSL servers
  choose the cipher based on their own preferences, rather than on the
  client's.

- Issue #11813: Fix inspect.getattr_static for modules. Patch by Andreas
  Stührk.

- Issue #7502: Fix equality comparison for DocTestCase instances.  Patch by
  Cédric Krier.

- Issue #11870: threading: Properly reinitialize threads internal locks and
  condition variables to avoid deadlocks in child processes.

- Issue #8035: urllib: Fix a bug where the client could remain stuck after a
  redirection or an error.

- Issue #13560: os.strerror() now uses the current locale encoding instead of
  UTF-8.

- Issue #13560: Add PyUnicode_DecodeLocale(), PyUnicode_DecodeLocaleAndSize()
  and PyUnicode_EncodeLocale() functions to the C API to decode/encode from/to
  the current locale encoding.

- Issue #8373: The filesystem path of AF_UNIX sockets now uses the filesystem
  encoding and the surrogateescape error handler, rather than UTF-8.  Patch
  by David Watson.

- Issue #10350: Read and save errno before calling a function which might
  overwrite it.  Original patch by Hallvard B Furuseth.

- Issue #11610: Introduce a more general way to declare abstract properties.

- Issue #13591: A bug in importlib has been fixed that caused import_module
  to load a module twice.

- Issue #4625: If IDLE cannot write to its recent file or breakpoint files,
  display a message popup and continue rather than crash.  Original patch by
  Roger Serwy.

- Issue #13449 sched.scheduler.run() method has a new "blocking" parameter which
  when set to False makes run() execute the scheduled events due to expire
  soonest (if any) and then return.  Patch by Giampaolo Rodolà.

- Issue #8684 sched.scheduler class can be safely used in multi-threaded
  environments.  Patch by Josiah Carlson and Giampaolo Rodolà.

- Alias resource.error to OSError ala PEP 3151.

- Issue #5689: Add support for lzma compression to the tarfile module.

- Issue #13248: Turn 3.2's PendingDeprecationWarning into 3.3's
  DeprecationWarning.  It covers 'cgi.escape', 'importlib.abc.PyLoader',
  'importlib.abc.PyPycLoader', 'nntplib.NNTP.xgtitle', 'nntplib.NNTP.xpath',
  and private attributes of 'smtpd.SMTPChannel'.

- Issue #5905, #13560: time.strftime() is now using the current locale
  encoding, instead of UTF-8, if the wcsftime() function is not available.

- Issue #8641: Update IDLE 3 syntax coloring to recognize b".." and not u"..".
  Patch by Tal Einat.

- Issue #13464: Add a readinto() method to http.client.HTTPResponse.  Patch
  by Jon Kuhn.

- tarfile.py: Correctly detect bzip2 compressed streams with blocksizes
  other than 900k.

- Issue #13439: Fix many errors in turtle docstrings.

- Issue #6715: Add a module 'lzma' for compression using the LZMA algorithm.
  Thanks to Per Øyvind Karlsen for the initial implementation.

- Issue #13487: Make inspect.getmodule robust against changes done to
  sys.modules while it is iterating over it.

- Issue #12618: Fix a bug that prevented py_compile from creating byte
  compiled files in the current directory.  Initial patch by Sjoerd de Vries.

- Issue #13444: When stdout has been closed explicitly, we should not attempt
  to flush it at shutdown and print an error.

- Issue #12567: The curses module uses Unicode functions for Unicode arguments
  when it is linked to the ncurses library. It encodes also Unicode strings to
  the locale encoding instead of UTF-8.

- Issue #12856: Ensure child processes do not inherit the parent's random
  seed for filename generation in the tempfile module.  Patch by Brian
  Harring.

- Issue #9957: SpooledTemporaryFile.truncate() now accepts an optional size
  parameter, as other file-like objects.  Patch by Ryan Kelly.

- Issue #13458: Fix a memory leak in the ssl module when decoding a
  certificate with a subjectAltName.  Patch by Robert Xiao.

- Issue #13415: os.unsetenv() doesn't ignore errors anymore.

- Issue #13245: sched.scheduler class constructor's timefunc and
  delayfunct parameters are now optional.
  scheduler.enter and scheduler.enterabs methods gained a new kwargs parameter.
  Patch contributed by Chris Clark.

- Issue #12328: Under Windows, refactor handling of Ctrl-C events and
  make _multiprocessing.win32.WaitForMultipleObjects interruptible when
  the wait_flag parameter is false.  Patch by sbt.

- Issue #13322: Fix BufferedWriter.write() to ensure that BlockingIOError is
  raised when the wrapped raw file is non-blocking and the write would block.
  Previous code assumed that the raw write() would raise BlockingIOError, but
  RawIOBase.write() is defined to returned None when the call would block.
  Patch by sbt.

- Issue #13358: HTMLParser now calls handle_data only once for each CDATA.

- Issue #4147: minidom's toprettyxml no longer adds whitespace around a text
  node when it is the only child of an element.  Initial patch by Dan
  Kenigsberg.

- Issue #13374: The Windows bytes API has been deprecated in the os module. Use
  Unicode filenames instead of bytes filenames to not depend on the ANSI code
  page anymore and to support any filename.

- Issue #13297: Use bytes type to send and receive binary data through XMLRPC.

- Issue #6397: Support "/dev/poll" polling objects in select module,
  under Solaris & derivatives.

- Issues #1745761, #755670, #13357, #12629, #1200313: HTMLParser now correctly
  handles non-valid attributes, including adjacent and unquoted attributes.

- Issue #13193: Fix distutils.filelist.FileList and packaging.manifest.Manifest
  under Windows.

- Issue #13384: Remove unnecessary __future__ import in Lib/random.py

- Issue #13149: Speed up append-only StringIO objects.

- Issue #13373: multiprocessing.Queue.get() could sometimes block indefinitely
  when called with a timeout.  Patch by Arnaud Ysmal.

- Issue #13254: Fix Maildir initialization so that maildir contents
  are read correctly.

- Issue #3067: locale.setlocale() now raises TypeError if the second
  argument is an invalid iterable. Its documentation and docstring
  were also updated. Initial patch by Jyrki Pulliainen.

- Issue #13140: Fix the daemon_threads attribute of ThreadingMixIn.

- Issue #13339: Fix compile error in posixmodule.c due to missing semicolon.
  Thanks to Robert Xiao.

- Byte compilation in packaging is now isolated from the calling Python -B or
  -O options, instead of being disallowed under -B or buggy under -O.

- Issue #10570: curses.putp() and curses.tparm() are now expecting a byte
  string, instead of a Unicode string.

- Issue #13295: http.server now produces valid HTML 4.01 strict.

- Issue #2892: preserve iterparse events in case of SyntaxError.

- Issue #13287: urllib.request and urllib.error now contains an __all__
  attribute to expose only relevant classes and functions.  Patch by Florent
  Xicluna.

- Issue #670664: Fix HTMLParser to correctly handle the content of
  ``<script>...</script>`` and ``<style>...</style>``.

- Issue #10817: Fix urlretrieve function to raise ContentTooShortError even
  when reporthook is None. Patch by Jyrki Pulliainen.

- Issue #13296: Fix IDLE to clear compile __future__ flags on shell restart.
  (Patch by Roger Serwy)

- Fix the xmlrpc.client user agent to return something similar to
  urllib.request user agent: "Python-xmlrpc/3.3".

- Issue #13293: Better error message when trying to marshal bytes using
  xmlrpc.client.

- Issue #13291: NameError in xmlrpc package.

- Issue #13258: Use callable() built-in in the standard library.

- Issue #13273: fix a bug that prevented HTMLParser to properly detect some
  tags when strict=False.

- Issue #11183: Add finer-grained exceptions to the ssl module, so that
  you don't have to inspect the exception's attributes in the common case.

- Issue #13216: Add cp65001 codec, the Windows UTF-8 (CP_UTF8).

- Issue #13226: Add RTLD_xxx constants to the os module. These constants can be
  used with sys.setdlopenflags().

- Issue #10278: Add clock_getres(), clock_gettime() and CLOCK_xxx constants to
  the time module. time.clock_gettime(time.CLOCK_MONOTONIC) provides a
  monotonic clock

- Issue #10332: multiprocessing: fix a race condition when a Pool is closed
  before all tasks have completed.

- Issue #13255: wrong docstrings in array module.

- Issue #8540: Remove deprecated Context._clamp attribute in Decimal module.

- Issue #13235: Added PendingDeprecationWarning to warn() method and function.

- Issue #9168: now smtpd is able to bind privileged port.

- Issue #12529: fix cgi.parse_header issue on strings with double-quotes and
  semicolons together. Patch by Ben Darnell and Petri Lehtinen.

- Issue #13227: functools.lru_cache() now has a option to distinguish
  calls with different argument types.

- Issue #6090: zipfile raises a ValueError when a document with a timestamp
  earlier than 1980 is provided. Patch contributed by Petri Lehtinen.

- Issue #13150: sysconfig no longer parses the Makefile and config.h files
  when imported, instead doing it at build time.  This makes importing
  sysconfig faster and reduces Python startup time by 20%.

- Issue #12448: smtplib now flushes stdout while running ``python -m smtplib``
  in order to display the prompt correctly.

- Issue #12454: The mailbox module is now using ASCII, instead of the locale
  encoding, to read and write MH mailboxes (.mh_sequences files).

- Issue #13194: zlib.compressobj().copy() and zlib.decompressobj().copy() are
  now available on Windows.

- issue #1673007: urllib2  to support HEAD request via new method argument.
  Patch contributions by David Stanek, Patrick Westerhoff and Ezio Melotti.

- Issue #12386: packaging does not fail anymore when writing the RESOURCES
  file.

- Issue #13158: Fix decoding and encoding of GNU tar specific base-256 number
  fields in tarfile.

- Issue #13025: mimetypes is now reading MIME types using the UTF-8 encoding,
  instead of the locale encoding.

- Issue #10653: On Windows, use strftime() instead of wcsftime() because
  wcsftime() doesn't format time zone correctly.

- Issue #13150: The tokenize module doesn't compile large regular expressions
  at startup anymore.

- Issue #11171: Fix distutils.sysconfig.get_makefile_filename when Python was
  configured with different prefix and exec-prefix.

- Issue #11254: Teach distutils and packaging to compile .pyc and .pyo files in
  PEP 3147-compliant __pycache__ directories.

- Issue #7367: Fix pkgutil.walk_paths to skip directories whose
  contents cannot be read.

- Issue #3163: The struct module gets new format characters 'n' and 'N'
  supporting C integer types ``ssize_t`` and ``size_t``, respectively.

- Issue #13099: Fix sqlite3.Cursor.lastrowid under a Turkish locale.
  Reported and diagnosed by Thomas Kluyver.

- Issue #13087: BufferedReader.seek() now always raises UnsupportedOperation
  if the underlying raw stream is unseekable, even if the seek could be
  satisfied using the internal buffer.  Patch by John O'Connor.

- Issue #7689: Allow pickling of dynamically created classes when their
  metaclass is registered with copyreg.  Patch by Nicolas M. Thiéry and Craig
  Citro.

- Issue #4147: minidom's toprettyxml no longer adds whitespace to text nodes.

- Issue #13034: When decoding some SSL certificates, the subjectAltName
  extension could be unreported.

- Issue #9871: Prevent IDLE 3 crash when given byte stings
  with invalid hex escape sequences, like b'\x0'.
  (Original patch by Claudiu Popa.)

- Issue #12306: Expose the runtime version of the zlib C library as a constant,
  ZLIB_RUNTIME_VERSION, in the zlib module. Patch by Torsten Landschoff.

- Issue #12959: Add collections.ChainMap to collections.__all__.

- Issue #8933: distutils' PKG-INFO files and packaging's METADATA files will
  now correctly report Metadata-Version: 1.1 instead of 1.0 if a Classifier or
  Download-URL field is present.

- Issue #12567: Add curses.unget_wch() function. Push a character so the next
  get_wch() will return it.

- Issue #9561: distutils and packaging now writes egg-info files using UTF-8,
  instead of the locale encoding.

- Issue #8286: The distutils command sdist will print a warning message instead
  of crashing when an invalid path is given in the manifest template.

- Issue #12841: tarfile unnecessarily checked the existence of numerical user
  and group ids on extraction. If one of them did not exist the respective id
  of the current user (i.e. root) was used for the file and ownership
  information was lost.

- Issue #12888: Fix a bug in HTMLParser.unescape that prevented it to escape
  more than 128 entities.  Patch by Peter Otten.

- Issue #12878: Expose a __dict__ attribute on io.IOBase and its subclasses.

- Issue #12636: IDLE reads the coding cookie when executing a Python script.

- Issue #12494: On error, call(), check_call(), check_output() and
  getstatusoutput() functions of the subprocess module now kill the process,
  read its status (to avoid zombis) and close pipes.

- Issue #12720: Expose low-level Linux extended file attribute functions in os.

- Issue #10946: The distutils commands bdist_dumb, bdist_wininst and bdist_msi
  now respect a --skip-build option given to bdist.  The packaging commands
  were fixed too.

- Issue #12847: Fix a crash with negative PUT and LONG_BINPUT arguments in
  the C pickle implementation.

- Issue #11564: Avoid crashes when trying to pickle huge objects or containers
  (more than 2**31 items).  Instead, in most cases, an OverflowError is raised.

- Issue #12287: Fix a stack corruption in ossaudiodev module when the FD is
  greater than FD_SETSIZE.

- Issue #12839: Fix crash in zlib module due to version mismatch.
  Fix by Richard M. Tew.

- Issue #9923: The mailcap module now correctly uses the platform path
  separator for the MAILCAP environment variable on non-POSIX platforms.

- Issue #12835: Follow up to #6560 that unconditionally prevents use of the
  unencrypted sendmsg/recvmsg APIs on SSL wrapped sockets. Patch by David
  Watson.

- Issue #12803: SSLContext.load_cert_chain() now accepts a password argument
  to be used if the private key is encrypted.  Patch by Adam Simpkins.

- Issue #11657: Fix sending file descriptors over 255 over a multiprocessing
  Pipe.

- Issue #12811: tabnanny.check() now promptly closes checked files. Patch by
  Anthony Briggs.

- Issue #6560: The sendmsg/recvmsg API is now exposed by the socket module
  when provided by the underlying platform, supporting processing of
  ancillary data in pure Python code. Patch by David Watson and Heiko Wundram.

- Issue #12326: On Linux, sys.platform doesn't contain the major version
  anymore. It is now always 'linux', instead of 'linux2' or 'linux3' depending
  on the Linux version used to build Python.

- Issue #12213: Fix a buffering bug with interleaved reads and writes that
  could appear on BufferedRandom streams.

- Issue #12778: Reduce memory consumption when JSON-encoding a large
  container of many small objects.

- Issue #12650: Fix a race condition where a subprocess.Popen could leak
  resources (FD/zombie) when killed at the wrong time.

- Issue #12744: Fix inefficient representation of integers between 2**31 and
  2**63 on systems with a 64-bit C "long".

- Issue #12646: Add an 'eof' attribute to zlib.Decompress, to make it easier to
  detect truncated input streams.

- Issue #11513: Fix exception handling ``tarfile.TarFile.gzopen()`` when
  the file cannot be opened.

- Issue #12687: Fix a possible buffering bug when unpickling text mode
  (protocol 0, mostly) pickles.

- Issue #10087: Fix the html output format of the calendar module.

- Issue #12540: Prevent zombie IDLE processes on Windows due to changes
  in os.kill().

- Add support for unary plus and unary minus to collections.Counter().
  Issue #13121: Also add support for inplace math operators.

- Issue #12683: urlparse updated to include svn as schemes that uses relative
  paths. (svn from 1.5 onwards support relative path).

- Issue #12655: Expose functions from sched.h in the os module: sched_yield(),
  sched_setscheduler(), sched_getscheduler(), sched_setparam(),
  sched_get_min_priority(), sched_get_max_priority(), sched_rr_get_interval(),
  sched_getaffinity(), sched_setaffinity().

- Add ThreadError to threading.__all__.

- Issues #11104, #8688: Fix the behavior of distutils' sdist command with
  manually-maintained MANIFEST files.

- Issue #11281: smtplib.STMP gets source_address parameter, which adds the
  ability to bind to specific source address on a machine with multiple
  interfaces. Patch by Paulo Scardine.

- Issue #12464: tempfile.TemporaryDirectory.cleanup() should not follow
  symlinks: fix it. Patch by Petri Lehtinen.

- Issue #8887: "pydoc somebuiltin.somemethod" (or help('somebuiltin.somemethod')
  in Python code) now finds the doc of the method.

- Issue #10968: Remove indirection in threading.  The public names (Thread,
  Condition, etc.) used to be factory functions returning instances of hidden
  classes (_Thread, _Condition, etc.), because (if Guido recalls correctly) this
  code pre-dates the ability to subclass extension types.  It is now possible to
  inherit from Thread and other classes, without having to import the private
  underscored names like multiprocessing did.

- Issue #9723: Add shlex.quote functions, to escape filenames and command
  lines.

- Issue #12603: Fix pydoc.synopsis() on files with non-negative st_mtime.

- Issue #12514: Use try/finally to assure the timeit module restores garbage
  collections when it is done.

- Issue #12607: In subprocess, fix issue where if stdin, stdout or stderr is
  given as a low fd, it gets overwritten.

- Issue #12590: IDLE editor window now always displays the first line
  when opening a long file.  With Tk 8.5, the first line was hidden.

- Issue #12576: Fix urlopen behavior on sites which do not send (or obfuscates)
  Connection:close header.

- Issue #12102: Document that buffered files must be flushed before being used
  with mmap. Patch by Steffen Daode Nurpmeso.

- Issue #12560: Build libpython.so on OpenBSD. Patch by Stefan Sperling.

- Issue #1813: Fix codec lookup under Turkish locales.

- Issue #12591: Improve support of "universal newlines" in the subprocess
  module: the piped streams can now be properly read from or written to.

- Issue #12591: Allow io.TextIOWrapper to work with raw IO objects (without
  a read1() method), and add a *write_through* parameter to mandate
  unbuffered writes.

- Issue #10883: Fix socket leaks in urllib.request when using FTP.

- Issue #12592: Make Python build on OpenBSD 5 (and future major releases).

- Issue #12372: POSIX semaphores are broken on AIX: don't use them.

- Issue #12551: Provide a get_channel_binding() method on SSL sockets so as
  to get channel binding data for the current SSL session (only the
  "tls-unique" channel binding is implemented).  This allows the implementation
  of certain authentication mechanisms such as SCRAM-SHA-1-PLUS.  Patch by
  Jacek Konieczny.

- Issue #665194: email.utils now has format_datetime and parsedate_to_datetime
  functions, allowing for round tripping of RFC2822 format dates.

- Issue #12571: Add a plat-linux3 directory mirroring the plat-linux2
  directory, so that "import DLFCN" and other similar imports work on
  Linux 3.0.

- Issue #7484: smtplib no longer puts <> around addresses in VRFY and EXPN
  commands; they aren't required and in fact postfix doesn't support that form.

- Issue #12273: Remove ast.__version__. AST changes can be accounted for by
  checking sys.version_info or sys._mercurial.

- Silence spurious "broken pipe" tracebacks when shutting down a
  ProcessPoolExecutor.

- Fix potential resource leaks in concurrent.futures.ProcessPoolExecutor
  by joining all queues and processes when shutdown() is called.

- Issue #11603: Fix a crash when __str__ is rebound as __repr__.  Patch by
  Andreas Stührk.

- Issue #11321: Fix a crash with multiple imports of the _pickle module when
  embedding Python.  Patch by Andreas Stührk.

- Issue #6755: Add get_wch() method to curses.window class. Patch by Iñigo
  Serna.

- Add cgi.closelog() function to close the log file.

- Issue #12502: asyncore: fix polling loop with AF_UNIX sockets.

- Issue #4376: ctypes now supports nested structures in a endian different than
  the parent structure. Patch by Vlad Riscutia.

- Raise ValueError when attempting to set the _CHUNK_SIZE attribute of a
  TextIOWrapper to a huge value, not TypeError.

- Issue #12504: Close file handles in a timely manner in packaging.database.
  This fixes a bug with the remove (uninstall) feature on Windows.

- Issues #12169 and #10510: Factor out code used by various packaging commands
  to make HTTP POST requests, and make sure it uses CRLF.

- Issue #12016: Multibyte CJK decoders now resynchronize faster. They only
  ignore the first byte of an invalid byte sequence. For example,
  b'\xff\n'.decode('gb2312', 'replace') gives '\ufffd\n' instead of '\ufffd'.

- Issue #12459: time.sleep() now raises a ValueError if the sleep length is
  negative, instead of an infinite sleep on Windows or raising an IOError on
  Linux for example, to have the same behaviour on all platforms.

- Issue #12451: pydoc: html_getfile() now uses tokenize.open() to support
  Python scripts using a encoding different than UTF-8 (read the coding cookie
  of the script).

- Issue #12493: subprocess: Popen.communicate() now also handles EINTR errors
  if the process has only one pipe.

- Issue #12467: warnings: fix a race condition if a warning is emitted at
  shutdown, if globals()['__file__'] is None.

- Issue #12451: pydoc: importfile() now opens the Python script in binary mode,
  instead of text mode using the locale encoding, to avoid encoding issues.

- Issue #12451: runpy: run_path() now opens the Python script in binary mode,
  instead of text mode using the locale encoding, to support other encodings
  than UTF-8 (scripts using the coding cookie).

- Issue #12451: xml.dom.pulldom: parse() now opens files in binary mode instead
  of the text mode (using the locale encoding) to avoid encoding issues.

- Issue #12147: Adjust the new-in-3.2 smtplib.send_message method for better
  conformance to the RFCs:  correctly handle Sender and Resent- headers.

- Issue #12352: Fix a deadlock in multiprocessing.Heap when a block is freed by
  the garbage collector while the Heap lock is held.

- Issue #12462: time.sleep() now calls immediatly the (Python) signal handler
  if it is interrupted by a signal, instead of having to wait until the next
  instruction.

- Issue #12442: new shutil.disk_usage function, providing total, used and free
  disk space statistics.

- Issue #12451: The XInclude default loader of xml.etree now decodes files from
  UTF-8 instead of the locale encoding if the encoding is not specified. It now
  also opens XML files for the parser in binary mode instead of the text mode
  to avoid encoding issues.

- Issue #12451: doctest.debug_script() doesn't create a temporary file
  anymore to avoid encoding issues.

- Issue #12451: pydoc.synopsis() now reads the encoding cookie if available,
  to read the Python script from the right encoding.

- Issue #12451: distutils now opens the setup script in binary mode to read the
  encoding cookie, instead of opening it in UTF-8.

- Issue #9516: On Mac OS X, change Distutils to no longer globally attempt to
  check or set the MACOSX_DEPLOYMENT_TARGET environment variable for the
  interpreter process.  This could cause failures in non-Distutils subprocesses
  and was unreliable since tests or user programs could modify the interpreter
  environment after Distutils set it.  Instead, have Distutils set the the
  deployment target only in the environment of each build subprocess.  It is
  still possible to globally override the default by setting
  MACOSX_DEPLOYMENT_TARGET before launching the interpreter; its value must be
  greater or equal to the default value, the value with which the interpreter
  was built.  Also, implement the same handling in packaging.

- Issue #12422: In the copy module, don't store objects that are their own copy
  in the memo dict.

- Issue #12303: Add sigwaitinfo() and sigtimedwait() to the signal module.

- Issue #12404: Remove C89 incompatible code from mmap module. Patch by Akira
  Kitada.

- Issue #1874: email now detects and reports as a defect the presence of
  any CTE other than 7bit, 8bit, or binary on a multipart.

- Issue #12383: Fix subprocess module with env={}: don't copy the environment
  variables, start with an empty environment.

- Issue #11637: Fix support for importing packaging setup hooks from the
  project directory.

- Issue #6771: Moved the curses.wrapper function from the single-function
  wrapper module into __init__, eliminating the module.  Since __init__ was
  already importing the function to curses.wrapper, there is no API change.

- Issue #11584: email.header.decode_header no longer fails if the header
  passed to it is a Header object, and Header/make_header no longer fail
  if given binary unknown-8bit input.

- Issue #11700: mailbox proxy object close methods can now be called multiple
  times without error.

- Issue #11767: Correct file descriptor leak in mailbox's __getitem__ method.

- Issue #12133: AbstractHTTPHandler.do_open() of urllib.request closes the HTTP
  connection if its getresponse() method fails with a socket error. Patch
  written by Ezio Melotti.

- Issue #12240: Allow multiple setup hooks in packaging's setup.cfg files.
  Original patch by Erik Bray.

- Issue #9284: Allow inspect.findsource() to find the source of doctest
  functions.

- Issue #11595: Fix assorted bugs in packaging.util.cfg_to_args, a
  compatibility helper for the distutils-packaging transition.  Original patch
  by Erik Bray.

- Issue #12287: In ossaudiodev, check that the device isn't closed in several
  methods.

- Issue #12009: Fixed regression in netrc file comment handling.

- Issue #12246: Warn and fail when trying to install a third-party project from
  an uninstalled Python (built in a source checkout).  Original patch by
  Tshepang Lekhonkhobe.

- Issue #10694: zipfile now ignores garbage at the end of a zipfile.

- Issue #12283: Fixed regression in smtplib quoting of leading dots in DATA.

- Issue #10424: Argparse now includes the names of the missing required
  arguments in the missing arguments error message.

- Issue #12168: SysLogHandler now allows NUL termination to be controlled using
  a new 'append_nul' attribute on the handler.

- Issue #11583: Speed up os.path.isdir on Windows by using GetFileAttributes
  instead of os.stat.

- Issue #12021: Make mmap's read() method argument optional. Patch by Petri
  Lehtinen.

- Issue #9205: concurrent.futures.ProcessPoolExecutor now detects killed
  children and raises BrokenProcessPool in such a situation.  Previously it
  would reliably freeze/deadlock.

- Issue #12040: Expose a new attribute ``sentinel`` on instances of
  ``multiprocessing.Process``.  Also, fix Process.join() to not use polling
  anymore, when given a timeout.

- Issue #11893: Remove obsolete internal wrapper class ``SSLFakeFile`` in the
  smtplib module.  Patch by Catalin Iacob.

- Issue #12080: Fix a Decimal.power() case that took an unreasonably long time
  to compute.

- Issue #12221: Remove __version__ attributes from pyexpat, pickle, tarfile,
  pydoc, tkinter, and xml.parsers.expat. This were useless version constants
  left over from the Mercurial transition

- Named tuples now work correctly with vars().

- Issue #12085: Fix an attribute error in subprocess.Popen destructor if the
  constructor has failed, e.g. because of an undeclared keyword argument. Patch
  written by Oleg Oshmyan.

- Issue #12028: Make threading._get_ident() public, rename it to
  threading.get_ident() and document it. This function was already used using
  _thread.get_ident().

- Issue #12171: IncrementalEncoder.reset() of CJK codecs (multibytecodec) calls
  encreset() instead of decreset().

- Issue #12218: Removed wsgiref.egg-info.

- Issue #12196: Add pipe2() to the os module.

- Issue #985064: Make plistlib more resilient to faulty input plists.
  Patch by Mher Movsisyan.

- Issue #1625: BZ2File and bz2.decompress() now support multi-stream files.
  Initial patch by Nir Aides.

- Issue #12175: BufferedReader.read(-1) now calls raw.readall() if available.

- Issue #12175: FileIO.readall() now only reads the file position and size
  once.

- Issue #12175: RawIOBase.readall() now returns None if read() returns None.

- Issue #12175: FileIO.readall() now raises a ValueError instead of an IOError
  if the file is closed.

- Issue #11109: New service_action method for BaseServer, used by ForkingMixin
  class for cleanup. Initial Patch by Justin Wark.

- Issue #12045: Avoid duplicate execution of command in
  ctypes.util._get_soname().  Patch by Sijin Joseph.

- Issue #10818: Remove the Tk GUI and the serve() function of the pydoc module,
  pydoc -g has been deprecated in Python 3.2 and it has a new enhanced web
  server.

- Issue #1441530: In imaplib, read the data in one chunk to speed up large
  reads and simplify code.

- Issue #12070: Fix the Makefile parser of the sysconfig module to handle
  correctly references to "bogus variable" (e.g. "prefix=$/opt/python").

- Issue #12100: Don't reset incremental encoders of CJK codecs at each call to
  their encode() method anymore, but continue to call the reset() method if the
  final argument is True.

- Issue #12049: Add RAND_bytes() and RAND_pseudo_bytes() functions to the ssl
  module.

- Issue #6501: os.device_encoding() returns None on Windows if the application
  has no console.

- Issue #12105: Add O_CLOEXEC to the os module.

- Issue #12079: Decimal('Infinity').fma(Decimal('0'), (3.91224318126786e+19+0j))
  now raises TypeError (reflecting the invalid type of the 3rd argument) rather
  than Decimal.InvalidOperation.

- Issue #12124: zipimport doesn't keep a reference to zlib.decompress() anymore
  to be able to unload the module.

- Add the packaging module, an improved fork of distutils (also known as
  distutils2).

- Issue #12065: connect_ex() on an SSL socket now returns the original errno
  when the socket's timeout expires (it used to return None).

- Issue #8809: The SMTP_SSL constructor and SMTP.starttls() now support
  passing a ``context`` argument pointing to an ssl.SSLContext instance.
  Patch by Kasun Herath.

- Issue #11088: don't crash when using F5 to run a script in IDLE on MacOSX
  with Tk 8.5.

- Issue #9516: Issue #9516: avoid errors in sysconfig when MACOSX_DEPLOYMENT_TARGET
  is set in shell.

- Issue #8650: Make zlib module 64-bit clean. compress(), decompress() and
  their incremental counterparts now raise OverflowError if given an input
  larger than 4GB, instead of silently truncating the input and returning
  an incorrect result.

- Issue #12050: zlib.decompressobj().decompress() now clears the unconsumed_tail
  attribute when called without a max_length argument.

- Issue #12062: Fix a flushing bug when doing a certain type of I/O sequence
  on a file opened in read+write mode (namely: reading, seeking a bit forward,
  writing, then seeking before the previous write but still within buffered
  data, and writing again).

- Issue #9971: Write an optimized implementation of BufferedReader.readinto().
  Patch by John O'Connor.

- Issue #1028: Tk returns invalid Unicode null in %A: UnicodeDecodeError.
  With Tk < 8.5 _tkinter.c:PythonCmd() raised UnicodeDecodeError, caused
  IDLE to exit.  Converted to valid Unicode null in PythonCmd().

- Issue #11799: urllib.request Authentication Handlers will raise a ValueError
  when presented with an unsupported Authentication Scheme. Patch contributed
  by Yuval Greenfield.

- Issue #10419, #6011: build_scripts command of distutils handles correctly
  non-ASCII path (path to the Python executable). Open and write the script in
  binary mode, but ensure that the shebang is decodable from UTF-8 and from the
  encoding of the script.

- Issue #8498: In socket.accept(), allow to specify 0 as a backlog value in
  order to accept exactly one connection.  Patch by Daniel Evers.

- Issue #12011: signal.signal() and signal.siginterrupt() raise an OSError,
  instead of a RuntimeError: OSError has an errno attribute.

- Issue #3709: a flush_headers method to BaseHTTPRequestHandler which manages
  the sending of headers to output stream and flushing the internal headers
  buffer. Patch contribution by Andrew Schaaf

- Issue #11743: Rewrite multiprocessing connection classes in pure Python.

- Issue #11164: Stop trying to use _xmlplus in the xml module.

- Issue #11888: Add log2 function to math module. Patch written by Mark
  Dickinson.

- Issue #12012: ssl.PROTOCOL_SSLv2 becomes optional.

- Issue #8407: The signal handler writes the signal number as a single byte
  instead of a nul byte into the wakeup file descriptor. So it is possible to
  wait more than one signal and know which signals were raised.

- Issue #8407: Add pthread_kill(), sigpending() and sigwait() functions to the
  signal module.

- Issue #11927: SMTP_SSL now uses port 465 by default as documented.  Patch
  by Kasun Herath.

- Issue #12002: ftplib's abort() method raises TypeError.

- Issue #11916: Add a number of MacOSX specific definitions to the errno module.
  Patch by Pierre Carrier.

- Issue #11999: fixed sporadic sync failure mailbox.Maildir due to its trying to
  detect mtime changes by comparing to the system clock instead of to the
  previous value of the mtime.

- Issue #11072: added MLSD command (RFC-3659) support to ftplib.

- Issue #8808: The IMAP4_SSL constructor now allows passing an SSLContext
  parameter to control parameters of the secure channel.  Patch by Sijin
  Joseph.

- ntpath.samefile failed to notice that "a.txt" and "A.TXT" refer to the same
  file on Windows XP. As noticed in issue #10684.

- Issue #12000: When a SSL certificate has a subjectAltName without any
  dNSName entry, ssl.match_hostname() should use the subject's commonName.
  Patch by Nicolas Bareil.

- Issue #10775: assertRaises, assertRaisesRegex, assertWarns, and
  assertWarnsRegex now accept a keyword argument 'msg' when used as context
  managers.  Initial patch by Winston Ewert.

- Issue #10684: shutil.move used to delete a folder on case insensitive
  filesystems when the source and destination name where the same except
  for the case.

- Issue #11647: objects created using contextlib.contextmanager now support
  more than one call to the function when used as a decorator. Initial patch
  by Ysj Ray.

- Issue #11930: Removed deprecated time.accept2dyear variable.
  Removed year >= 1000 restriction from datetime.strftime.

- logging: don't define QueueListener if Python has no thread support.

- functools.cmp_to_key() now works with collections.Hashable().

- Issue #11277: mmap.mmap() calls fcntl(fd, F_FULLFSYNC) on Mac OS X to get
  around a mmap bug with sparse files. Patch written by Steffen Daode Nurpmeso.

- Issue #8407: Add signal.pthread_sigmask() function to fetch and/or change the
  signal mask of the calling thread.

- Issue #11858: configparser.ExtendedInterpolation expected lower-case section
  names.

- Issue #11324: ConfigParser(interpolation=None) now works correctly.

- Issue #11811: ssl.get_server_certificate() is now IPv6-compatible.  Patch
  by Charles-François Natali.

- Issue #11763: don't use difflib in TestCase.assertMultiLineEqual if the
  strings are too long.

- Issue #11236: getpass.getpass responds to ctrl-c or ctrl-z on terminal.

- Issue #11856: Speed up parsing of JSON numbers.

- Issue #11005: threading.RLock()._release_save() raises a RuntimeError if the
  lock was not acquired.

- Issue #11258: Speed up ctypes.util.find_library() under Linux by a factor
  of 5 to 10.  Initial patch by Jonas H.

- Issue #11382: Trivial system calls, such as dup() or pipe(), needn't
  release the GIL.  Patch by Charles-François Natali.

- Issue #11223: Add threading._info() function providing informations about
  the thread implementation.

- Issue #11731: simplify/enhance email parser/generator API by introducing
  policy objects.

- Issue #11768: The signal handler of the signal module only calls
  Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or
  parallel calls. PyErr_SetInterrupt() writes also into the wake up file.

- Issue #11492: fix several issues with header folding in the email package.

- Issue #11852: Add missing imports and update tests.

- Issue #11875: collections.OrderedDict's __reduce__ was temporarily
  mutating the object instead of just working on a copy.

- Issue #11467: Fix urlparse behavior when handling urls which contains scheme
  specific part only digits. Patch by Santoso Wijaya.

- collections.Counter().copy() now works correctly for subclasses.

- Issue #11474: Fix the bug with url2pathname() handling of '/C|/' on Windows.
  Patch by Santoso Wijaya.

- Issue #11684: complete email.parser bytes API by adding BytesHeaderParser.

- The bz2 module now handles 4GiB+ input buffers correctly.

- Issue #9233: Fix json.loads('{}') to return a dict (instead of a list), when
  _json is not available.

- Issue #11830: Remove unnecessary introspection code in the decimal module.

- Issue #11703: urllib2.geturl() does not return correct url when the original
  url contains #fragment.

- Issue #10019: Fixed regression in json module where an indent of 0 stopped
  adding newlines and acted instead like 'None'.

- Issue #11186: pydoc ignores a module if its name contains a surrogate
  character in the index of modules.

- Issue #11815: Use a light-weight SimpleQueue for the result queue in
  concurrent.futures.ProcessPoolExecutor.

- Issue #5162: Treat services like frozen executables to allow child spawning
  from multiprocessing.forking on Windows.

- logging.basicConfig now supports an optional 'handlers' argument taking an
  iterable of handlers to be added to the root logger. Additional parameter
  checks were also added to basicConfig.

- Issue #11814: Fix likely typo in multiprocessing.Pool._terminate().

- Issue #11747: Fix range formatting in difflib.context_diff() and
  difflib.unified_diff().

- Issue #8428: Fix a race condition in multiprocessing.Pool when terminating
  worker processes: new processes would be spawned while the pool is being
  shut down.  Patch by Charles-François Natali.

- Issue #2650: re.escape() no longer escapes the '_'.

- Issue #11757: select.select() now raises ValueError when a negative timeout
  is passed (previously, a select.error with EINVAL would be raised).  Patch
  by Charles-François Natali.

- Issue #7311: fix html.parser to accept non-ASCII attribute values.

- Issue #11605: email.parser.BytesFeedParser was incorrectly converting
  multipart subparts with an 8-bit CTE into unicode instead of preserving the
  bytes.

- Issue #1690608: email.util.formataddr is now RFC 2047 aware:  it now has a
  charset parameter that defaults to utf-8 and is used as the charset for RFC
  2047 encoding when the realname contains non-ASCII characters.

- Issue #10963: Ensure that subprocess.communicate() never raises EPIPE.

- Issue #10791: Implement missing method GzipFile.read1(), allowing GzipFile
  to be wrapped in a TextIOWrapper.  Patch by Nadeem Vawda.

- Issue #11707: Added a fast C version of functools.cmp_to_key().
  Patch by Filip Gruszczyński.

- Issue #11688: Add sqlite3.Connection.set_trace_callback().  Patch by
  Torsten Landschoff.

- Issue #11746: Fix SSLContext.load_cert_chain() to accept elliptic curve
  private keys.

- Issue #5863: Rewrite BZ2File in pure Python, and allow it to accept
  file-like objects using a new ``fileobj`` constructor argument.  Patch by
  Nadeem Vawda.

- unittest.TestCase.assertSameElements has been removed.

- sys.getfilesystemencoding() raises a RuntimeError if initfsencoding() was not
  called yet: detect bootstrap (startup) issues earlier.

- Issue #11393: Add the new faulthandler module.

- Issue #11618: Fix the timeout logic in threading.Lock.acquire() under Windows.

- Removed the 'strict' argument to email.parser.Parser, which has been
  deprecated since Python 2.4.

- Issue #11256: Fix inspect.getcallargs on functions that take only keyword
  arguments.

- Issue #11696: Fix ID generation in msilib.

- itertools.accumulate now supports an optional *func* argument for
  a user-supplied binary function.

- Issue #11692: Remove unnecessary demo functions in subprocess module.

- Issue #9696: Fix exception incorrectly raised by xdrlib.Packer.pack_int when
  trying to pack a negative (in-range) integer.

- Issue #11675: multiprocessing.[Raw]Array objects created from an integer size
  are now zeroed on creation.  This matches the behaviour specified by the
  documentation.

- Issue #7639: Fix short file name generation in bdist_msi

- Issue #11659: Fix ResourceWarning in test_subprocess introduced by #11459.
  Patch by Ben Hayden.

- Issue #11635: Don't use polling in worker threads and processes launched by
  concurrent.futures.

- Issue #6811: Allow importlib to change a code object's co_filename attribute
  to match the path to where the source code currently is, not where the code
  object originally came from.

- Issue #8754: Have importlib use the repr of a module name in error messages.

- Issue #11591: Prevent "import site" from modifying sys.path when python
  was started with -S.

- collections.namedtuple() now adds a _source attribute to the generated
  class.  This make the source more accessible than the outdated
  "verbose" option which prints to stdout but doesn't make the source
  string available.

- Issue #11371: Mark getopt error messages as localizable.  Patch by Filip
  Gruszczyński.

- Issue #11333: Add __slots__ to collections ABCs.

- Issue #11628: cmp_to_key generated class should use __slots__.

- Issue #11666: let help() display named tuple attributes and methods
  that start with a leading underscore.

- Issue #11662: Make urllib and urllib2 ignore redirections if the
  scheme is not HTTP, HTTPS or FTP (CVE-2011-1521).

- Issue #5537: Fix time2isoz() and time2netscape() functions of
  httplib.cookiejar for expiration year greater than 2038 on 32-bit systems.

- Issue #4391: Use proper gettext plural forms in optparse.

- Issue #11127: Raise a TypeError when trying to pickle a socket object.

- Issue #11563: Connection:close header is sent by requests using URLOpener
  class which helps in closing of sockets after connection is over. Patch
  contributions by Jeff McNeil and Nadeem Vawda.

- Issue #11459: A ``bufsize`` value of 0 in subprocess.Popen() really creates
  unbuffered pipes, such that select() works properly on them.

- Issue #5421: Fix misleading error message when one of socket.sendto()'s
  arguments has the wrong type.  Patch by Nikita Vetoshkin.

- Issue #10812: Add some extra posix functions to the os module.

- Issue #10979: unittest stdout buffering now works with class and module
  setup and teardown.

- Issue #11577: fix ResourceWarning triggered by improved binhex test coverage

- Issue #11243: fix the parameter querying methods of Message to work if
  the headers contain un-encoded non-ASCII data.

- Issue #11401: fix handling of headers with no value; this fixes a regression
  relative to Python2 and the result is now the same as it was in Python2.

- Issue #9298: base64 bodies weren't being folded to line lengths less than 78,
  which was a regression relative to Python2.  Unlike Python2, the last line
  of the folded body now ends with a carriage return.

- Issue #11560: shutil.unpack_archive now correctly handles the format
  parameter. Patch by Evan Dandrea.

- Issue #5870: Add `subprocess.DEVNULL` constant.

- Issue #11133: fix two cases where inspect.getattr_static can trigger code
  execution. Patch by Andreas Stührk.

- Issue #11569: use absolute path to the sysctl command in multiprocessing to
  ensure that it will be found regardless of the shell PATH. This ensures
  that multiprocessing.cpu_count works on default installs of MacOSX.

- Issue #11501: disutils.archive_utils.make_zipfile no longer fails if zlib is
  not installed. Instead, the zipfile.ZIP_STORED compression is used to create
  the ZipFile. Patch by Natalia B. Bidart.

- Issue #11289: `smtp.SMTP` class becomes a context manager so it can be used
  in a `with` statement.  Contributed by Giampaolo Rodola.

- Issue #11554: Fixed support for Japanese codecs; previously the body output
  encoding was not done if euc-jp or shift-jis was specified as the charset.

- Issue #11509: Significantly increase test coverage of fileinput.
  Patch by Denver Coneybeare at PyCon 2011 Sprints.

- Issue #11407: `TestCase.run` returns the result object used or created.
  Contributed by Janathan Hartley.

- Issue #11500: Fixed a bug in the os x proxy bypass code for fully qualified
  IP addresses in the proxy exception list.

- Issue #11491: dbm.error is no longer raised when dbm.open is called with
  the "n" as the flag argument and the file exists. The behavior matches
  the documentation and general logic.

- Issue #1162477: Postel Principle adjustment to email date parsing: handle the
  fact that some non-compliant MUAs use '.' instead of ':' in time specs.

- Issue #11131: Fix sign of zero in decimal.Decimal plus and minus
  operations when the rounding mode is ROUND_FLOOR.

- Issue #9935: Speed up pickling of instances of user-defined classes.

- Issue #5622: Fix curses.wrapper to raise correct exception if curses
  initialization fails.

- Issue #11408: In threading.Lock.acquire(), only call gettimeofday() when
  really necessary.  Patch by Charles-François Natali.

- Issue #11391: Writing to a mmap object created with
  ``mmap.PROT_READ|mmap.PROT_EXEC`` would segfault instead of raising a
  TypeError.  Patch by Charles-François Natali.

- Issue #9795: add context manager protocol support for nntplib.NNTP class.

- Issue #11306: mailbox in certain cases adapts to an inability to open
  certain files in read-write mode.  Previously it detected this by
  checking for EACCES, now it also checks for EROFS.

- Issue #11265: asyncore now correctly handles EPIPE, EBADF and EAGAIN errors
  on accept(), send() and recv().

- Issue #11377: Deprecate platform.popen() and reimplement it with os.popen().

- Issue #8513: On UNIX, subprocess supports bytes command string.

- Issue #10866: Add socket.sethostname().  Initial patch by Ross Lagerwall.

- Issue #11140: Lock.release() now raises a RuntimeError when attempting
  to release an unacquired lock, as claimed in the threading documentation.
  The _thread.error exception is now an alias of RuntimeError.  Patch by
  Filip Gruszczyński.  Patch for _dummy_thread by Aymeric Augustin.

- Issue #8594: ftplib now provides a source_address parameter to specify which
  (address, port) to bind to before connecting.

- Issue #11326: Add the missing connect_ex() implementation for SSL sockets,
  and make it work for non-blocking connects.

- Issue #11297: Add collections.ChainMap().

- Issue #10755: Add the posix.flistdir() function.  Patch by Ross Lagerwall.

- Issue #4761: Add the ``*at()`` family of functions (openat(), etc.) to the
  posix module.  Patch by Ross Lagerwall.

- Issue #7322: Trying to read from a socket's file-like object after a timeout
  occurred now raises an error instead of silently losing data.

- Issue #11291: poplib.POP no longer suppresses errors on quit().

- Issue #11177: asyncore's create_socket() arguments can now be omitted.

- Issue #6064: Add a ``daemon`` keyword argument to the threading.Thread
  and multiprocessing.Process constructors in order to override the
  default behaviour of inheriting the daemonic property from the current
  thread/process.

- Issue #10956: Buffered I/O classes retry reading or writing after a signal
  has arrived and the handler returned successfully.

- Issue #10784: New os.getpriority() and os.setpriority() functions.

- Issue #11114: Fix catastrophic performance of tell() on text files (up
  to 1000x faster in some cases).  It is still one to two order of magnitudes
  slower than binary tell().

- Issue #10882: Add os.sendfile function.

- Issue #10868: Allow usage of the register method of an ABC as a class
  decorator.

- Issue #11224: Fixed a regression in tarfile that affected the file-like
  objects returned by TarFile.extractfile() regarding performance, memory
  consumption and failures with the stream interface.

- Issue #10924: Adding salt and Modular Crypt Format to crypt library.
  Moved old C wrapper to _crypt, and added a Python wrapper with
  enhanced salt generation and simpler API for password generation.

- Issue #11074: Make 'tokenize' so it can be reloaded.

- Issue #11085: Moved collections abstract base classes into a separate
  module called collections.abc, following the pattern used by importlib.abc.
  For backwards compatibility, the names are imported into the collections
  module.

- Issue #4681: Allow mmap() to work on file sizes and offsets larger than
  4GB, even on 32-bit builds.  Initial patch by Ross Lagerwall, adapted for
  32-bit Windows.

- Issue #11169: compileall module uses repr() to format filenames and paths to
  escape surrogate characters and show spaces.

- Issue #11089: Fix performance issue limiting the use of ConfigParser()
  with large config files.

- Issue #10276: Fix the results of zlib.crc32() and zlib.adler32() on buffers
  larger than 4GB.  Patch by Nadeem Vawda.

- Issue #11388: Added a clear() method to MutableSequence

- Issue #11174: Add argparse.MetavarTypeHelpFormatter, which uses type names
  for the names of optional and positional arguments in help messages.

- Issue #9348: Raise an early error if argparse nargs and metavar don't match.

- Issue #8982: Improve the documentation for the argparse Namespace object.

- Issue #9343: Document that argparse parent parsers must be configured before
  their children.

- Issue #9026: Fix order of argparse sub-commands in help messages.

- Issue #9347: Fix formatting for tuples in argparse type= error messages.

- Issue #12191: Added shutil.chown() to change user and/or group owner of a
  given path also specifying their names.

- Issue #13988: The _elementtree accelerator is used whenever available.
  Now xml.etree.cElementTree becomes a deprecated alias to ElementTree.

Build
-----

- Issue #6807: Run msisupport.mak earlier.

- Issue #10580: Minor grammar change in Windows installer.

- Issue #13326: Clean __pycache__ directories correctly on OpenBSD.

- PEP 393: the configure option --with-wide-unicode is removed.

- Issue #12852: Set _XOPEN_SOURCE to 700, instead of 600, to get POSIX 2008
  functions on OpenBSD (e.g. fdopendir).

- Issue #11863: Remove support for legacy systems deprecated in Python 3.2
  (following PEP 11).  These systems are systems using Mach C Threads,
  SunOS lightweight processes, GNU pth threads and IRIX threads.

- Issue #8746: Correct faulty configure checks so that os.chflags() and
  os.lchflags() are once again built on systems that support these
  functions (BSD and OS X).  Also add new stat file flags for OS X
  (UF_HIDDEN and UF_COMPRESSED).

- Issue #10645: Installing Python does no longer create a
  Python-X.Y.Z-pyX.Y.egg-info file in the lib-dynload directory.

- Do not accidentally include the directory containing sqlite.h twice when
  building sqlite3.

- Issue #11217: For 64-bit/32-bit Mac OS X universal framework builds,
  ensure "make install" creates symlinks in --prefix bin for the "-32"
  files in the framework bin directory like the installer does.

- Issue #11347: Use --no-as-needed when linking libpython3.so.

- Issue #11411: Fix 'make DESTDIR=' with a relative destination.

- Issue #11268: Prevent Mac OS X Installer failure if Documentation
  package had previously been installed.

- Issue #11495: OSF support is eliminated. It was deprecated in Python 3.2.


IDLE
----

- Issue #11718: IDLE's open module dialog couldn't find the __init__.py
  file in a package.

Tools/Demos
-----------

- Issue #14053: patchcheck.py ("make patchcheck") now works with MQ patches.
  Patch by Francisco Martín Brugué.

- Issue #13930: 2to3 is now able to write its converted output files to another
  directory tree as well as copying unchanged files and altering the file
  suffix.  See its new -o, -W and --add-suffix options.  This makes it more
  useful in many automated code translation workflows.

- Issue #13628: python-gdb.py is now able to retrieve more frames in the Python
  traceback if Python is optimized.

- Issue #11996: libpython (gdb), replace "py-bt" command by "py-bt-full" and
  add a smarter "py-bt" command printing a classic Python traceback.

- Issue #11179: Make ccbench work under Python 3.1 and 2.7 again.

- Issue #10639: reindent.py no longer converts newlines and will raise
  an error if attempting to convert a file with mixed newlines.
  "--newline" option added to specify new line character.

Extension Modules
-----------------

- Issue #13840: The error message produced by ctypes.create_string_buffer
  when given a Unicode string has been fixed.

- Issue #9975: socket: Fix incorrect use of flowinfo and scope_id. Patch by
  Vilmos Nebehaj.

- Issue #7777: socket: Add Reliable Datagram Sockets (PF_RDS) support.

- Issue #13159: FileIO and BZ2Compressor/BZ2Decompressor now use a linear-time
  buffer growth strategy instead of a quadratic-time one.

- Issue #10141: socket: Add SocketCAN (PF_CAN) support. Initial patch by
  Matthias Fuchs, updated by Tiago Gonçalves.

- Issue #13070: Fix a crash when a TextIOWrapper caught in a reference cycle
  would be finalized after the reference to its underlying BufferedRWPair's
  writer got cleared by the GC.

- Issue #12881: ctypes: Fix segfault with large structure field names.

- Issue #13058: ossaudiodev: fix a file descriptor leak on error. Patch by
  Thomas Jarosch.

- Issue #13013: ctypes: Fix a reference leak in PyCArrayType_from_ctype.
  Thanks to Suman Saha for finding the bug and providing a patch.

- Issue #13022: Fix: _multiprocessing.recvfd() doesn't check that
  file descriptor was actually received.

- Issue #1172711: Add 'long long' support to the array module.
  Initial patch by Oren Tirosh and Hirokazu Yamamoto.

- Issue #12483: ctypes: Fix a crash when the destruction of a callback
  object triggers the garbage collector.

- Issue #12950: Fix passing file descriptors in multiprocessing, under
  OpenIndiana/Illumos.

- Issue #12764: Fix a crash in ctypes when the name of a Structure field is not
  a string.

- Issue #11241: subclasses of ctypes.Array can now be subclassed.

- Issue #9651: Fix a crash when ctypes.create_string_buffer(0) was passed to
  some functions like file.write().

- Issue #10309: Define _GNU_SOURCE so that mremap() gets the proper
  signature.  Without this, architectures where sizeof void* != sizeof int are
  broken.  Patch given by Hallvard B Furuseth.

- Issue #12051: Fix segfault in json.dumps() while encoding highly-nested
  objects using the C accelerations.

- Issue #12017: Fix segfault in json.loads() while decoding highly-nested
  objects using the C accelerations.

- Issue #1838: Prevent segfault in ctypes, when _as_parameter_ on a class is set
  to an instance of the class.

Tests
-----

- Issue #11689: Fix a variable scoping error in an sqlite3 test

- Issue #13786: Remove unimplemented 'trace' long option from regrtest.py.

- Issue #13725: Fix regrtest to recognize the documented -d flag.
  Patch by Erno Tukia.

- Issue #13304: Skip test case if user site-packages disabled (-s or
  PYTHONNOUSERSITE).  (Patch by Carl Meyer)

- Issue #5661: Add a test for ECONNRESET/EPIPE handling to test_asyncore. Patch
  by Xavier de Gaye.

- Issue #13218: Fix test_ssl failures on Debian/Ubuntu.

- Re-enable lib2to3's test_parser.py tests, though with an expected failure
  (see issue 13125).

- Issue #12656: Add tests for IPv6 and Unix sockets to test_asyncore.

- Issue #6484: Add unit tests for mailcap module (patch by Gregory Nofi)

- Issue #11651: Improve the Makefile test targets to run more of the test suite
  more quickly. The --multiprocess option is now enabled by default, reducing
  the amount of time needed to run the tests. "make test" and "make quicktest"
  now include some resource-intensive tests, but no longer run the test suite
  twice to check for bugs in .pyc generation. Tools/scripts/run_test.py provides
  an easy platform-independent way to run test suite with sensible defaults.

- Issue #12331: The test suite for the packaging module can now run from an
  installed Python.

- Issue #12331: The test suite for lib2to3 can now run from an installed
  Python.

- Issue #12626: In regrtest, allow to filter tests using a glob filter
  with the ``-m`` (or ``--match``) option.  This works with all test cases
  using the unittest module.  This is useful with long test suites
  such as test_io or test_subprocess.

- Issue #12624: It is now possible to fail after the first failure when
  running in verbose mode (``-v`` or ``-W``), by using the ``--failfast``
  (or ``-G``) option to regrtest.  This is useful with long test suites
  such as test_io or test_subprocess.

- Issue #12587: Correct faulty test file and reference in test_tokenize.
  (Patch by Robert Xiao)

- Issue #12573: Add resource checks for dangling Thread and Process objects.

- Issue #12549: Correct test_platform to not fail when OS X returns 'x86_64'
  as the processor type on some Mac systems.

- Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary
  failure in name resolution.

- Issue #11812: Solve transient socket failure to connect to 'localhost'
  in test_telnetlib.py.

- Solved a potential deadlock in test_telnetlib.py. Related to issue #11812.

- Avoid failing in test_robotparser when mueblesmoraleda.com is flaky and
  an overzealous DNS service (e.g. OpenDNS) redirects to a placeholder
  Web site.

- Avoid failing in test_urllibnet.test_bad_address when some overzealous
  DNS service (e.g. OpenDNS) resolves a non-existent domain name.  The test
  is now skipped instead.

- Issue #12440: When testing whether some bits in SSLContext.options can be
  reset, check the version of the OpenSSL headers Python was compiled against,
  rather than the runtime version of the OpenSSL library.

- Issue #11512: Add a test suite for the cgitb module. Patch by Robbie Clemons.

- Issue #12497: Install test/data to prevent failures of the various codecmaps
  tests.

- Issue #12496: Install test/capath directory to prevent test_connect_capath
  testcase failure in test_ssl.

- Issue #12469: Run wakeup and pending signal tests in a subprocess to run the
  test in a fresh process with only one thread and to not change signal
  handling of the parent process.

- Issue #8716: Avoid crashes caused by Aqua Tk on OSX when attempting to run
  test_tk or test_ttk_guionly under a username that is not currently logged
  in to the console windowserver (as may be the case under buildbot or ssh).

- Issue #12407: Explicitly skip test_capi.EmbeddingTest under Windows.

- Issue #12400: regrtest -W doesn't rerun the tests twice anymore, but captures
  the output and displays it on failure instead. regrtest -v doesn't print the
  error twice anymore if there is only one error.

- Issue #12141: Install copies of template C module file so that
  test_build_ext of test_distutils and test_command_build_ext of
  test_packaging are no longer silently skipped when
  run outside of a build directory.

- Issue #8746: Add additional tests for os.chflags() and os.lchflags().
  Patch by Garrett Cooper.

- Issue #10736: Fix test_ttk test_widgets failures with Cocoa Tk 8.5.9
  2.8 +  on Mac OS X.  (Patch by Ronald Oussoren)

- Issue #12057: Add tests for ISO 2022 codecs (iso2022_jp, iso2022_jp_2,
  iso2022_kr).

- Issue #12096: Fix a race condition in test_threading.test_waitfor(). Patch
  written by Charles-François Natali.

- Issue #11614: import __hello__ prints "Hello World!". Patch written by
  Andreas Stührk.

- Issue #5723: Improve json tests to be executed with and without accelerations.

- Issue #12041: Make test_wait3 more robust.

- Issue #11873: Change regex in test_compileall to fix occasional failures when
  when the randomly generated temporary path happened to match the regex.

- Issue #11958: Fix FTP tests for IPv6, bind to "::1" instead of "localhost".
  Patch written by Charles-Francois Natali.

- Issue #8407, #11859: Fix tests of test_io using threads and an alarm: use
  pthread_sigmask() to ensure that the SIGALRM signal is received by the main
  thread.

- Issue #11811: Factor out detection of IPv6 support on the current host
  and make it available as ``test.support.IPV6_ENABLED``.  Patch by
  Charles-François Natali.

- Issue #10914: Add a minimal embedding test to test_capi.

- Issue #11223: Skip test_lock_acquire_interruption() and
  test_rlock_acquire_interruption() of test_threadsignals if a thread lock is
  implemented using a POSIX mutex and a POSIX condition variable. A POSIX
  condition variable cannot be interrupted by a signal (e.g. on Linux, the
  futex system call is restarted).

- Issue #11790: Fix sporadic failures in test_multiprocessing.WithProcessesTestCondition.

- Fix possible "file already exists" error when running the tests in parallel.

- Issue #11719: Fix message about unexpected test_msilib skip on non-Windows
  platforms. Patch by Nadeem Vawda.

- Issue #11727: Add a --timeout option to regrtest: if a test takes more than
  TIMEOUT seconds, dumps the traceback of all threads and exits.

- Issue #11653: fix -W with -j in regrtest.

- The email test suite now lives in the Lib/test/test_email package.  The test
  harness code has also been modernized to allow use of new unittest features.

- regrtest now discovers test packages as well as test modules.

- Issue #11577: improve test coverage of binhex.py. Patch by Arkady Koplyarov.

- New test_crashers added to exercise the scripts in the Lib/test/crashers
  directory and confirm they fail as expected

- Issue #11578: added test for the timeit module.  Patch by Michael Henry.

- Issue #11503: improve test coverage of posixpath.py. Patch by Evan Dandrea.

- Issue #11505: improves test coverage of string.py, increases granularity of
  string.Formatter tests. Initial patch by Alicia Arlen.

- Issue #11548: Improve test coverage of the shutil module. Patch by
  Evan Dandrea.

- Issue #11554: Reactivated test_email_codecs.

- Issue #11505: improves test coverage of string.py. Patch by Alicia
  Arlen

- Issue #11490: test_subprocess:test_leaking_fds_on_error no longer gives a
  false positive if the last directory in the path is inaccessible.

- Issue #11223: Fix test_threadsignals to fail, not hang, when the
  non-semaphore implementation of locks is used under POSIX.

- Issue #10911: Add tests on CGI with non-ASCII characters. Patch written by
  Pierre Quentel.

- Issue #9931: Fix hangs in GUI tests under Windows in certain conditions.
  Patch by Hirokazu Yamamoto.

- Issue #10512: Properly close sockets under test.test_cgi.

- Issue #10992: Make tests pass under coverage.

- Issue #10826: Prevent sporadic failure in test_subprocess on Solaris due
  to open door files.

- Issue #10990: Prevent tests from clobbering a set trace function.

C-API
-----

- Add PyObject_GenericGetDict and PyObject_GeneriSetDict. They are generic
  implementations for the getter and setter of a ``__dict__`` descriptor of C
  types.

- Issue #13727: Add 3 macros to access PyDateTime_Delta members:
  PyDateTime_DELTA_GET_DAYS, PyDateTime_DELTA_GET_SECONDS,
  PyDateTime_DELTA_GET_MICROSECONDS.

- Issue #10542: Add 4 macros to work with surrogates: Py_UNICODE_IS_SURROGATE,
  Py_UNICODE_IS_HIGH_SURROGATE, Py_UNICODE_IS_LOW_SURROGATE,
  Py_UNICODE_JOIN_SURROGATES.

- Issue #12724: Add Py_RETURN_NOTIMPLEMENTED macro for returning NotImplemented.

- PY_PATCHLEVEL_REVISION has been removed, since it's meaningless with
  Mercurial.

- Issue #12173: The first argument of PyImport_ImportModuleLevel is now `const
  char *` instead of `char *`.

- Issue #12380: PyArg_ParseTuple now accepts a bytearray for the 'c' format.

Documentation
-------------

- Issues #13491 and #13995: Fix many errors in sqlite3 documentation.
  Initial patch for #13491 by Johannes Vogel.

- Issue #13402: Document absoluteness of sys.executable.

- Issue #13883: PYTHONCASEOK also works on OS X.

- Issue #12949: Document the kwonlyargcount argument for the PyCode_New
  C API function.

- Issue #13513: Fix io.IOBase documentation to correctly link to the
  io.IOBase.readline method instead of the readline module.

- Issue #13237: Reorganise subprocess documentation to emphasise convenience
  functions and the most commonly needed arguments to Popen.

- Issue #13141: Demonstrate recommended style for socketserver examples.

- Issue #11818: Fix tempfile examples for Python 3.


What's New in Python 3.2?
=========================

*Release date: 20-Feb-2011*

Core and Builtins
-----------------

- Issue #11249: Fix potential crashes when using the limited API.

Build
-----

- Issue #11222: Fix non-framework shared library build on Mac OS X.

- Issue #11184: Fix large-file support on AIX.

- Issue #941346: Fix broken shared library build on AIX.

Documentation
-------------

- Issue #10709: Add updated AIX notes in Misc/README.AIX.


What's New in Python 3.2 Release Candidate 3?
=============================================

*Release date: 13-Feb-2011*

Core and Builtins
-----------------

- Issue #11134: Add missing fields to typeslots.h.

- Issue #11135: Remove redundant doc field from PyType_Spec.

- Issue #11067: Add PyType_GetFlags, to support PyUnicode_Check in the limited
  ABI.

- Issue #11118: Fix bogus export of None in python3.dll.

Library
-------

- Issue #11116: any error during addition of a message to a mailbox now causes a
  rollback, instead of leaving the mailbox partially modified.

- Issue #11132: Fix passing of "optimize" parameter when recursing in
  compileall.compile_dir().

- Issue #11110: Fix a potential decref of a NULL in sqlite3.

- Issue #8275: Fix passing of callback arguments with ctypes under Win64.  Patch
  by Stan Mihai.

Build
-----

- Issue #11079: The /Applications/Python x.x folder created by the Mac OS X
  installers now includes a link to the installed documentation and no longer
  includes an Extras directory.  The Tools directory is now installed in the
  framework under share/doc.

- Issue #11121: Fix building with --enable-shared.

Tests
-----

- Issue #10971: test_zipimport_support is once again compatible with the refleak
  hunter feature of test.regrtest.


What's New in Python 3.2 Release Candidate 2?
=============================================

*Release date: 30-Jan-2011*

Core and Builtins
-----------------

- Issue #10451: memoryview objects could allow to mutate a readable buffer.
  Initial patch by Ross Lagerwall.

Library
-------

- Issue #9124: mailbox now accepts binary input and reads and writes mailbox
  files in binary mode, using the email package's binary support to parse
  arbitrary email messages.  StringIO and text file input is deprecated,
  and string input fails early if non-ASCII characters are used, where
  previously it would fail when the email was processed in a later step.

- Issue #10845: Mitigate the incompatibility between the multiprocessing
  module on Windows and the use of package, zipfile or directory execution
  by special casing main modules that actually *are* called __main__.py.

- Issue #11045: Protect logging call against None argument.

- Issue #11052: Correct IDLE menu accelerators on Mac OS X for Save
  commands.

- Issue #11053: Fix IDLE "Syntax Error" windows to behave as in 2.x,
  preventing a confusing hung appearance on OS X with the windows
  obscured.

- Issue #10940: Workaround an IDLE hang on Mac OS X 10.6 when using the
  menu accelerators for Open Module, Go to Line, and New Indent Width.
  The accelerators still work but no longer appear in the menu items.

- Issue #10989: Fix a crash on SSLContext.load_verify_locations(None, True).

- Issue #11020: Command-line pyclbr was broken because of missing 2-to-3
  conversion.

- Issue #11019: Fixed BytesGenerator so that it correctly handles a Message
  with a None body.

- Issue #11014: Make 'filter' argument in tarfile.Tarfile.add() into a
  keyword-only argument.  The preceding positional argument was deprecated,
  so it made no sense to add filter as a positional argument.

- Issue #11004: Repaired edge case in deque.count().

- Issue #10974: IDLE no longer crashes if its recent files list includes files
  with non-ASCII characters in their path names.

- Have hashlib.algorithms_available and hashlib.algorithms_guaranteed both
  return sets instead of one returning a tuple and the other a frozenset.

- Issue #10987: Fix the recursion limit handling in the _pickle module.

- Issue #10983: Fix several bugs making tunnel requests in http.client.

- Issue #10955: zipimport uses ASCII encoding instead of cp437 to decode
  filenames, at bootstrap, if the codec registry is not ready yet. It is still
  possible to have non-ASCII filenames using the Unicode flag (UTF-8 encoding)
  for all file entries in the ZIP file.

- Issue #10949: Improved robustness of rotating file handlers.

- Issue #10955: Fix a potential crash when trying to mmap() a file past its
  length.  Initial patch by Ross Lagerwall.

- Issue #10898: Allow compiling the posix module when the C library defines
  a symbol named FSTAT.

- Issue #10980: the HTTP server now encodes headers with iso-8859-1 (latin1)
  encoding.  This is the preferred encoding of PEP 3333 and the base encoding
  of HTTP 1.1.

- To match the behaviour of HTTP server, the HTTP client library now also
  encodes headers with iso-8859-1 (latin1) encoding.  It was already doing
  that for incoming headers which makes this behaviour now consistent in
  both incoming and outgoing direction.

- Issue #9509: argparse now properly handles IOErrors raised by
  argparse.FileType.

- Issue #10961: The new pydoc server now better handles exceptions raised
  during request handling.

- Issue #10680: Fix mutually exclusive arguments for argument groups in
  argparse.

Build
-----

- Issue #11054: Allow Mac OS X installer builds to again work on 10.5 with
  the system-provided Python.


What's New in Python 3.2 Release Candidate 1
============================================

*Release date: 16-Jan-2011*

Core and Builtins
-----------------

- Issue #10889: range indexing and slicing now works correctly on ranges with
  a length that exceeds sys.maxsize.

- Issue #10892: Don't segfault when trying to delete __abstractmethods__ from a
  class.

- Issue #8020: Avoid a crash where the small objects allocator would read
  non-Python managed memory while it is being modified by another thread.  Patch
  by Matt Bandy.

- Issue #10841: On Windows, set the binary mode on stdin, stdout, stderr and all
  io.FileIO objects (to not translate newlines, \r\n <=> \n).  The Python parser
  translates newlines (\r\n => \n).

- Remove buffer API from stable ABI for now, see #10181.

- Issue #8651: PyArg_Parse*() functions raise an OverflowError if the file
  doesn't have PY_SSIZE_T_CLEAN define and the size doesn't fit in an int
  (length bigger than 2^31-1 bytes).

- Issue #9015, #9611: FileIO.readinto(), FileIO.write(), os.write() and
  stdprinter.write() clamp the length to INT_MAX on Windows.

- Issue #8278: On Windows and with a NTFS filesystem, os.stat() and os.utime()
  can now handle dates after 2038.

- Issue #10780: PyErr_SetFromWindowsErrWithFilename() and
  PyErr_SetExcFromWindowsErrWithFilename() decode the filename from the
  filesystem encoding instead of UTF-8.

- Issue #10779: PyErr_WarnExplicit() decodes the filename from the filesystem
  encoding instead of UTF-8.

- Add sys.flags attribute for the new -q command-line option.

- Issue #11506: Trying to assign to a bytes literal should result in a
  SyntaxError.

Library
-------

- Issue #10916: mmap should not segfault when a file is mapped using 0 as length
  and a non-zero offset, and an attempt to read past the end of file is made
  (IndexError is raised instead).  Patch by Ross Lagerwall.

- Issue #10154, #10090: change the normalization of UTF-8 to "UTF-8" instead
  of "UTF8" in the locale module as the latter is not supported MacOSX and OpenBSD.

- Issue #10907: Warn OS X 10.6 IDLE users to use ActiveState Tcl/Tk 8.5, rather
  than the currently problematic Apple-supplied one, when running with the
  64-/32-bit installer variant.

- Issue #4953: cgi.FieldStorage and cgi.parse() parse the request as bytes, not
  as unicode, and accept binary files. Add encoding and errors attributes to
  cgi.FieldStorage. Patch written by Pierre Quentel (with many inputs by Glenn
  Linderman).

- Add encoding and errors arguments to urllib.parse_qs() and urllib.parse_qsl().

- Issue #10899: No function type annotations in the standard library.  Removed
  function type annotations from _pyio.py.

- Issue #10875: Update Regular Expression HOWTO; patch by 'SilentGhost'.

- Issue #10872: The repr() of TextIOWrapper objects now includes the mode
  if available.

- Issue #10869: Fixed bug where ast.increment_lineno modified the root node
  twice.

- Issue #5871: email.header.Header.encode now raises an error if any
  continuation line in the formatted value has no leading white space and looks
  like a header.  Since Generator uses Header to format all headers, this check
  is made for all headers in any serialized message at serialization time.  This
  provides protection against header injection attacks.

- Issue #10859: Make ``contextlib.GeneratorContextManager`` officially
  private by renaming it to ``_GeneratorContextManager``.

- Issue #10042: Fixed the total_ordering decorator to handle cross-type
  comparisons that could lead to infinite recursion.

- Issue #10686: the email package now :rfc:`2047`\ -encodes headers with
  non-ASCII bytes (parsed by a BytesParser) when doing conversion to 7bit-clean
  presentation, instead of replacing them with ?s.

- email.header.Header was incorrectly encoding folding whitespace when
  rfc2047-encoding header values with embedded newlines, leaving them without
  folding whitespace.  It now uses the continuation_ws, as it does for
  continuation lines that it creates itself.

- Issue #1777412, #10827: Changed the rules for 2-digit years. The
  time.asctime(), time.ctime() and time.strftime() functions will now format
  any year when ``time.accept2dyear`` is False and will accept years >= 1000
  otherwise. ``time.mktime`` and ``time.strftime`` now accept full range
  supported by the OS. With Visual Studio or on Solaris, the year is limited to
  the range [1; 9999]. Conversion of 2-digit years to 4-digit is deprecated.

- Issue #7858: Raise an error properly when os.utime() fails under Windows
  on an existing file.

- Issue #3839: wsgiref should not override a Content-Length header set by
  the application.  Initial patch by Clovis Fabricio.

- Issue #10492: bdb.Bdb.run() only traces the execution of the code, not the
  compilation (if the input is a string).

- Issue #7995: When calling accept() on a socket with a timeout, the returned
  socket is now always blocking, regardless of the operating system.

- Issue #10756: atexit normalizes the exception before displaying it. Patch by
  Andreas Stührk.

- Issue #10790: email.header.Header.append's charset logic now works correctly
  for charsets whose output codec is different from its input codec.

- Issue #10819: SocketIO.name property returns -1 when its closed, instead of
  raising a ValueError, to fix repr().

- Issue #8650: zlib.compress() and zlib.decompress() raise an OverflowError if
  the input buffer length doesn't fit into an unsigned int (length bigger than
  2^32-1 bytes).

- Issue #6643: Reinitialize locks held within the threading module after fork to
  avoid a potential rare deadlock or crash on some platforms.

- Issue #10806, issue #9905: Fix subprocess pipes when some of the standard file
  descriptors (0, 1, 2) are closed in the parent process.  Initial patch by Ross
  Lagerwall.

- `unittest.TestCase` can be instantiated without a method name; for simpler
  exploration from the interactive interpreter.

- Issue #10798: Reject supporting concurrent.futures if the system has too
  few POSIX semaphores.

- Issue #10807: Remove base64, bz2, hex, quopri, rot13, uu and zlib codecs from
  the codec aliases. They are still accessible via codecs.lookup().

- Issue #10801: In zipfile, support different encodings for the header and the
  filenames.

- Issue #6285: IDLE no longer crashes on missing help file; patch by Scott
  David Daniels.

- Fix collections.OrderedDict.setdefault() so that it works in subclasses that
  define __missing__().

- Issue #10786: unittest.TextTestRunner default stream no longer bound at import
  time. `sys.stderr` now looked up at instantiation time.  Fix contributed by
  Mark Roddy.

- Issue #10753: Characters ';', '=' and ',' in the PATH_INFO environment variable
  won't be quoted when the URI is constructed by the wsgiref.util's request_uri
  method. According to RFC 3986, these characters can be a part of params in
  PATH component of URI and need not be quoted.

- Issue #10738: Fix webbrowser.Opera.raise_opts.

- Issue #9824: SimpleCookie now encodes , and ; in values to cater to how
  browsers actually parse cookies.

- Issue #9333: os.symlink now available regardless of user privileges.  The
  function now raises OSError on Windows >=6.0 when the user is unable to create
  symbolic links. XP and 2003 still raise NotImplementedError.

- Issue #10783: struct.pack() no longer implicitly encodes unicode to UTF-8.

- Issue #10730: Add SVG mime types to mimetypes module.

- Issue #10768: Make the Tkinter ScrolledText widget work again.

- Issue #10777: Fix "dictionary changed size during iteration" bug in
  ElementTree register_namespace().

- Issue #10626: test_logging now preserves logger disabled states.

- Issue #10774: test_logging now removes temp files created during tests.

- Issue #5258/#10642: if site.py encounters a .pth file that generates an error,
  it now prints the filename, line number, and traceback to stderr and skips
  the rest of that individual file, instead of stopping processing entirely.

- Issue #10763: subprocess.communicate() closes stdout and stderr if both are
  pipes (bug specific to Windows).

- Issue #1693546: fix email.message RFC 2231 parameter encoding to be in better
  compliance (no "s around encoded values).

- Improved the diff message in the unittest module's assertCountEqual().

- Issue #1155362: email.utils.parsedate_tz now handles a missing space before
  the '-' of a timezone field as well as before a '+'.

- Issue #4871: The zipfile module now gives a more useful error message if
  an attempt is made to use a string to specify the archive password.

- Issue #10750: The ``raw`` attribute of buffered IO objects is now read-only.

- Deprecated assertDictContainsSubset() in the unittest module.

C-API
-----

- PyObject_CallMethod now passes along any underlying AttributeError from
  PyObject_GetAttr, instead of replacing it with something less informative

- Issue #10913: Deprecate misleading functions PyEval_AcquireLock() and
  PyEval_ReleaseLock().  The thread-state aware APIs should be used instead.

- Issue #10333: Remove ancient GC API, which has been deprecated since Python
  2.2.

Build
-----

- Issue #10843: Update third-party library versions used in OS X 32-bit
  installer builds: bzip2 1.0.6, readline 6.1.2, SQLite 3.7.4 (with FTS3/FTS4
  and RTREE enabled), and ncursesw 5.5 (wide-char support enabled).

- Issue #10820: Fix OS X framework installs to support version-specific
  scripts (#10679).

- Issue #7716: Under Solaris, don't assume existence of /usr/xpg4/bin/grep in
  the configure script but use $GREP instead.  Patch by Fabian Groffen.

- Issue #10475: Don't hardcode compilers for LDSHARED/LDCXXSHARED on NetBSD
  and DragonFly BSD.  Patch by Nicolas Joly.

- Issue #10679: The "idle", "pydoc" and "2to3" scripts are now installed with
  a version-specific suffix on "make altinstall".

- Issue #10655: Fix the build on PowerPC on Linux with GCC when building with
  timestamp profiling (--with-tsc): the preprocessor test for the PowerPC
  support now looks for "__powerpc__" as well as "__ppc__": the latter seems to
  only be present on OS X; the former is the correct one for Linux with GCC.

- Issue #1099: Fix the build on MacOSX when building a framework with pydebug
  using GCC 4.0.

Tools/Demos
-----------

- Issue #10843: Install the Tools directory on OS X in the applications Extras
  (/Applications/Python 3.n/Extras/) where the Demo directory had previous been
  installed.

- Issue #7962: The Demo directory is gone.  Most of the old and unmaintained
  demos have been removed, others integrated in documentation or a new
  Tools/demo subdirectory.

- Issue #10502: Addition of the unittestgui tool. Originally by Steve Purcell.
  Updated for test discovery by Mark Roddy and Python 3 compatibility by Brian
  Curtin.

Tests
-----

- Issue #11910: Fix test_heapq to skip the C tests when _heapq is missing.

- Fix test_startfile to wait for child process to terminate before finishing.

- Issue #10822: Fix test_posix:test_getgroups failure under Solaris.  Patch
  by Ross Lagerwall.

- Make the --coverage flag work for test.regrtest.

- Issue #1677694: Refactor and improve test_timeout.  Original patch by
  Björn Lindqvist.

- Issue #5485: Add tests for the UseForeignDTD method of expat parser objects.
  Patch by Jean-Paul Calderone and Sandro Tosi.

- Issue #6293: Have regrtest.py echo back sys.flags.  This is done by default in
  whole runs and enabled selectively using ``--header`` when running an explicit
  list of tests.  Original patch by Collin Winter.


What's New in Python 3.2 Beta 2?
================================

*Release date: 19-Dec-2010*

Core and Builtins
-----------------

- Issue #8844: Regular and recursive lock acquisitions can now be interrupted
  by signals on platforms using pthreads.  Patch by Reid Kleckner.

- Issue #4236: PyModule_Create2 now checks the import machinery directly
  rather than the Py_IsInitialized flag, avoiding a Fatal Python
  error in certain circumstances when an import is done in __del__.

- Issue #5587: add a repr to dict_proxy objects.  Patch by David Stanek and
  Daniel Urban.

Library
-------

- Issue #3243:  Support iterable bodies in httplib. Patch Contributions by
  Xuanji Li and Chris AtLee.

- Issue #10611: SystemExit exception will no longer kill a unittest run.

- Issue #9857: It is now possible to skip a test in a setUp, tearDown or clean
  up function.

- Issue #10573: use actual/expected consistently in unittest methods.
  The order of the args of assertCountEqual is also changed.

- Issue #9286: email.utils.parseaddr no longer concatenates blank-separated
  words in the local part of email addresses, thereby preserving the input.

- Issue #6791: Limit header line length (to 65535 bytes) in http.client
  and http.server, to avoid denial of services from the other party.

- Issue #10404: Use ctl-button-1 on OSX for the context menu in Idle.

- Issue #9907: Fix tab handling on OSX when using editline by calling
  rl_initialize first, then setting our custom defaults, then reading .editrc.

- Issue #4188: Avoid creating dummy thread objects when logging operations
  from the threading module (with the internal verbose flag activated).

- Issue #10711: Remove HTTP 0.9 support from http.client.  The ``strict``
  parameter to HTTPConnection and friends is deprecated.

- Issue #9721: Fix the behavior of urljoin when the relative url starts with a
  ';' character. Patch by Wes Chow.

- Issue #10714: Limit length of incoming request in http.server to 65536 bytes
  for security reasons.  Initial patch by Ross Lagerwall.

- Issue #9558: Fix distutils.command.build_ext with VS 8.0.

- Issue #10667: Fast path for collections.Counter().

- Issue #10695: passing the port as a string value to telnetlib no longer
  causes debug mode to fail.

- Issue #1078919: add_header now automatically RFC2231 encodes parameters
  that contain non-ascii values.

- Issue #10188 (partial resolution): tempfile.TemporaryDirectory emits
  a warning on sys.stderr rather than throwing a misleading exception
  if cleanup fails due to nulling out of modules during shutdown.
  Also avoids an AttributeError when mkdtemp call fails and issues
  a ResourceWarning on implicit cleanup via __del__.

- Issue #10107: Warn about unsaved files in IDLE on OSX.

- Issue #7213: subprocess.Popen's default for close_fds has been changed.
  It is now True in most cases other than on Windows when input, output or
  error handles are provided.

- Issue #6559: subprocess.Popen has a new pass_fds parameter (actually
  added in 3.2beta1) to allow specifying a specific list of file descriptors
  to keep open in the child process.

- Issue #1731717: Fixed the problem where subprocess.wait() could cause an
  OSError exception when The OS had been told to ignore SIGCLD in our process
  or otherwise not wait for exiting child processes.

Tests
-----

- Issue #775964: test_grp now skips YP/NIS entries instead of failing when
  encountering them.

Tools/Demos
-----------

- Issue #6075: IDLE on Mac OS X now works with both Carbon AquaTk and
  Cocoa AquaTk.

- Issue #10710: ``Misc/setuid-prog.c`` is removed from the source tree.

- Issue #10706: Remove outdated script runtests.sh.  Either ``make test``
  or ``python -m test`` should be used instead.

Build
-----

- The Windows build now uses Tcl/Tk 8.5.9 and sqlite3 3.7.4.

- Issue #9234: argparse supports alias names for subparsers.


What's New in Python 3.2 Beta 1?
================================

*Release date: 05-Dec-2010*

Core and Builtins
-----------------

- Issue #10630: Return dict views from the dict proxy keys()/values()/items()
  methods.

- Issue #10596: Fix float.__mod__ to have the same behaviour as float.__divmod__
  with respect to signed zeros.  -4.0 % 4.0 should be 0.0, not -0.0.

- Issue #1772833: Add the -q command-line option to suppress copyright and
  version output in interactive mode.

- Provide an *optimize* parameter in the built-in compile() function.

- Fixed several corner case issues on Windows in os.stat/os.lstat related to
  reparse points.

- PEP 384 (Defining a Stable ABI) is implemented.

- Issue #2690: Range objects support negative indices and slicing.

- Issue #9915: Speed up sorting with a key.

- Issue #8685: Speed up set difference ``a - b`` when source set ``a`` is much
  larger than operand ``b``.  Patch by Andrew Bennetts.

- Issue #10518: Bring back the callable() builtin.

- Issue #7094: Added alternate formatting (specified by '#') to ``__format__``
  method of float, complex, and Decimal. This allows more precise control over
  when decimal points are displayed.

- Issue #10474: range.count() should return integers.

- Issue #1574217: isinstance now catches only AttributeError, rather than
  masking all errors.

Library
-------

- logging: added "handler of last resort". See http://bit.ly/last-resort-handler

- test.support: Added TestHandler and Matcher classes for better support of
  assertions about logging.

- Issue #4391: Use proper plural forms in argparse.

- Issue #10601: sys.displayhook uses 'backslashreplace' error handler on
  UnicodeEncodeError.

- Add the "display" and "undisplay" pdb commands.

- Issue #7245: Add a SIGINT handler in pdb that allows to break a program again
  after a "continue" command.

- Add the "interact" pdb command.

- Issue #7905: Actually respect the keyencoding parameter to shelve.Shelf.

- Issue #1569291: Speed up array.repeat().

- Provide an interface to set the optimization level of compilation in
  py_compile, compileall and zipfile.PyZipFile.

- Issue #7904: Changes to urllib.parse.urlsplit to handle schemes as defined by
  RFC3986. Anything before :// is considered a scheme and is followed by an
  authority (or netloc) and by '/' led path, which is optional.

- Issue #6045: dbm.gnu databases now support get() and setdefault() methods.

- Issue #10620: `python -m unittest` can accept file paths instead of module
  names for running specific tests.

- Issue #9424: Deprecate the `unittest.TestCase` methods `assertEquals`,
  `assertNotEquals`, `assertAlmostEquals`, `assertNotAlmostEquals` and `assert_`
  and replace them with the correct methods in the Python test suite.

- Issue #10272: The ssl module now raises socket.timeout instead of a generic
  SSLError on socket timeouts.

- Issue #10528: Allow translators to reorder placeholders in localizable
  messages from argparse.

- Issue #10497: Fix incorrect use of gettext in argparse.

- Issue #10478: Reentrant calls inside buffered IO objects (for example by
  way of a signal handler) now raise a RuntimeError instead of freezing the
  current process.

- logging: Added getLogRecordFactory/setLogRecordFactory with docs and tests.

- Issue #10549: Fix pydoc traceback when text-documenting certain classes.

- Issue #2001: New HTML server with enhanced Web page features.  Patch by Ron
  Adam.

- Issue #10360: In WeakSet, do not raise TypeErrors when testing for membership
  of non-weakrefable objects.

- Issue #940286: pydoc.Helper.help() ignores input/output init parameters.

- Issue #1745035: Add a command size and data size limit to smtpd.py, to prevent
  DoS attacks.  Patch by Savio Sena.

- Issue #4925: Add filename to error message when executable can't be found in
  subprocess.

- Issue #10391: Don't dereference invalid memory in error messages in the ast
  module.

- Issue #10027: st_nlink was not being set on Windows calls to os.stat or
  os.lstat. Patch by Hirokazu Yamamoto.

- Issue #9333: Expose os.symlink only when the SeCreateSymbolicLinkPrivilege is
  held by the user's account, i.e., when the function can actually be used.

- Issue #8879: Add os.link support for Windows.

- Issue #7911: ``unittest.TestCase.longMessage`` defaults to True for improved
  failure messages by default. Patch by Mark Roddy.

- Issue #1486713: HTMLParser now has an optional tolerant mode where it tries to
  guess at the correct parsing of invalid html.

- Issue #10554: Add context manager support to subprocess.Popen objects.

- Issue #8989: email.utils.make_msgid now has a domain parameter that can
  override the domain name used in the generated msgid.

- Issue #9299: Add exist_ok parameter to os.makedirs to suppress the 'File
  exists' exception when a target directory already exists with the specified
  mode. Patch by Ray Allen.

- Issue #9573: os.fork() now works correctly when triggered as a side effect of
  a module import.

- Issue #10464: netrc now correctly handles lines with embedded '#' characters.

- Added itertools.accumulate().

- Issue #4113: Added custom ``__repr__`` method to ``functools.partial``.
  Original patch by Daniel Urban.

- Issue #10273: Rename `assertRegexpMatches` and `assertRaisesRegexp` to
  `assertRegex` and `assertRaisesRegex`.

- Issue #10535: Enable silenced warnings in unittest by default.

- Issue #9873: The URL parsing functions in urllib.parse now accept ASCII byte
  sequences as input in addition to character strings.

- Issue #10586: The statistics API for the new functools.lru_cache has been
  changed to a single cache_info() method returning a named tuple.

- Issue #10323: itertools.islice() now consumes the minimum number of inputs
  before stopping.  Formerly, the final state of the underlying iterator was
  undefined.

- Issue #10565: The collections.Iterator ABC now checks for both __iter__ and
  __next__.

- Issue #10242: Fixed implementation of unittest.ItemsEqual and gave it a new
  more informative name, unittest.CountEqual.

- Issue #10561: In pdb, clear the breakpoints by the breakpoint number.

- Issue #2986: difflib.SequenceMatcher gets a new parameter, autojunk, which can
  be set to False to turn off the previously undocumented 'popularity'
  heuristic. Patch by Terry Reedy and Eli Bendersky.

- Issue #10534: in difflib, expose bjunk and bpopular sets; deprecate
  undocumented and now redundant isbjunk and isbpopular methods.

- Issue #9846: zipfile is now correctly closing underlying file objects.

- Issue #10459: Update CJK character names to Unicode 6.0.

- Issue #4493: urllib.request adds '/' in front of path components which does not
  start with '/. Common behavior exhibited by browsers and other clients.

- Issue #6378: idle.bat now runs with the appropriate Python version rather than
  the system default. Patch by Sridhar Ratnakumar.

- Issue #10470: 'python -m unittest' will now run test discovery by default,
  when no extra arguments have been provided.

- Issue #3709: BaseHTTPRequestHandler will buffer the headers and write to
  output stream only when end_headers is invoked. This is a speedup and an
  internal optimization.  Patch by endian.

- Issue #10220: Added inspect.getgeneratorstate. Initial patch by Rodolpho
  Eckhardt.

- Issue #10453: compileall now uses argparse instead of getopt, and thus
  provides clean output when called with '-h'.

- Issue #8078: Add constants for higher baud rates in the termios module.  Patch
  by Rodolpho Eckhardt.

- Issue #10407: Fix two NameErrors in distutils.

- Issue #10371: Deprecated undocumented functions in the trace module.

- Issue #10467: Fix BytesIO.readinto() after seeking into a position after the
  end of the file.

- configparser: 100% test coverage.

- Issue #10499: configparser supports pluggable interpolation handlers. The
  default classic interpolation handler is called BasicInterpolation. Another
  interpolation handler added (ExtendedInterpolation) which supports the syntax
  used by zc.buildout (e.g. interpolation between sections).

- configparser: the SafeConfigParser class has been renamed to ConfigParser.
  The legacy ConfigParser class has been removed but its interpolation mechanism
  is still available as LegacyInterpolation.

- configparser: Usage of RawConfigParser is now discouraged for new projects
  in favor of ConfigParser(interpolation=None).

- Issue #1682942: configparser supports alternative option/value delimiters.

- Issue #5412: configparser supports mapping protocol access.

- Issue #9411: configparser supports specifying encoding for read operations.

- Issue #9421: configparser's getint(), getfloat() and getboolean() methods
  accept vars and default arguments just like get() does.

- Issue #9452: configparser supports reading from strings and dictionaries
  (thanks to the mapping protocol API, the latter can be used to copy data
  between parsers).

- configparser: accepted INI file structure is now customizable, including
  comment prefixes, name of the DEFAULT section, empty lines in multiline
  values, and indentation.

- Issue #10326: unittest.TestCase instances can be pickled.

- Issue #9926: Wrapped TestSuite subclass does not get __call__ executed.

- Issue #9920: Skip tests for cmath.atan and cmath.atanh applied to complex
  zeros on systems where the log1p function fails to respect the sign of zero.
  This fixes a test failure on AIX.

- Issue #9732: Addition of getattr_static to the inspect module.

- Issue #10446: Module documentation generated by pydoc now links to a
  version-specific online reference manual.

- Make the 'No module named' exception message from importlib consistent.

- Issue #10443: Add the SSLContext.set_default_verify_paths() method.

- Issue #10440: Support RUSAGE_THREAD as a constant in the resource module.
  Patch by Robert Collins.

- Issue #10429: IMAP.starttls() stored the capabilities as bytes objects, rather
  than strings.

C-API
-----

- Issue #10557: Added a new API function, PyUnicode_TransformDecimalToASCII(),
  which transforms non-ASCII decimal digits in a Unicode string to their ASCII
  equivalents.

- Issue #9518: Extend the PyModuleDef_HEAD_INIT macro to explicitly
  zero-initialize all fields, fixing compiler warnings seen when building
  extension modules with gcc with "-Wmissing-field-initializers" (implied by
  "-W").

- Issue #10255: Fix reference leak in Py_InitializeEx().  Patch by Neil
  Schemenauer.

- structseq.h is now included in Python.h.

- Loosen PyArg_ValidateKeywordArguments to allow dict subclasses.

Tests
-----

- regrtest.py once again ensures the test directory is removed from sys.path
  when it is invoked directly as the __main__ module.

- `python -m test` can be used to run the test suite as well as `python -m
  test.regrtest`.

- Do not fail test_socket when the IP address of the local hostname cannot be
  looked up.

- Issue #8886: Use context managers throughout test_zipfile. Patch by Eric
  Carstensen.

Build
-----

- Issue #10325: Fix two issues in the fallback definitions for PY_ULLONG_MAX and
  PY_LLONG_MAX that made them unsuitable for use in preprocessor conditionals.

Documentation
-------------

- Issue #10299: List the built-in functions in a table in functions.rst.


What's New in Python 3.2 Alpha 4?
=================================

*Release date: 13-Nov-2010*

Core and Builtins
-----------------

- Issue #10372: Import the warnings module only after the IO library is
  initialized, so as to avoid bootstrap issues with the '-W' option.

- Issue #10293: Remove obsolete field in the PyMemoryView structure, unused
  undocumented value PyBUF_SHADOW, and strangely-looking code in
  PyMemoryView_GetContiguous.

- Issue #6081: Add str.format_map(), similar to ``str.format(**mapping)``.

- If FileIO.__init__ fails, close the file descriptor.

- Issue #10221: dict.pop(k) now has a key error message that includes the
  missing key (same message d[k] returns for missing keys).

- Issue #5437: A preallocated MemoryError instance should not keep traceback
  data (including local variables caught in the stack trace) alive infinitely.

- Issue #10186: Fix the SyntaxError caret when the offset is equal to the length
  of the offending line.

- Issue #10089: Add support for arbitrary -X options on the command line.  They
  can be retrieved through a new attribute ``sys._xoptions``.

- Issue #4388: On Mac OS X, decode command line arguments from UTF-8, instead of
  the locale encoding.  If the LANG (and LC_ALL and LC_CTYPE) environment
  variable is not set, the locale encoding is ISO-8859-1, whereas most programs
  (including Python) expect UTF-8.  Python already uses UTF-8 for the filesystem
  encoding and to encode command line arguments on this OS.

- Issue #9713, #10114: Parser functions (e.g. PyParser_ASTFromFile) expect
  filenames encoded to the filesystem encoding with the surrogateescape error
  handler (to support undecodable bytes), instead of UTF-8 in strict mode.

- Issue #9997: Don't let the name "top" have special significance in scope
  resolution.

- Issue #9862: Compensate for broken PIPE_BUF in AIX by hard coding its value as
  the default 512 when compiling on AIX.

- Use locale encoding instead of UTF-8 to encode and decode filenames if
  Py_FileSystemDefaultEncoding is not set.

- Issue #10095: fp_setreadl() doesn't reopen the file, instead reuse the file
  descriptor.

- Issue #9418: Moved private string methods ``_formatter_parser`` and
  ``_formatter_field_name_split`` into a new ``_string`` module.

- Issue #9992: Remove PYTHONFSENCODING environment variable.

Library
-------

- Issue #12943: python -m tokenize support has been added to tokenize.

- Issue #10465: fix broken delegating of attributes by gzip._PaddedFile.

- Issue #10356: Decimal.__hash__(-1) should return -2.

- Issue #1553375: logging: Added stack_info kwarg to display stack information.

- Issue #5111: IPv6 Host in the Header is wrapped inside [ ]. Patch by Chandru.

- Fix Fraction.__hash__ so that Fraction.__hash__(-1) is -2.  (See also issue
  #10356.)

- Issue #4471: Add the IMAP.starttls() method to enable encryption on standard
  IMAP4 connections.  Original patch by Lorenzo M. Catucci.

- Issue #1466065: Add 'validate' option to base64.b64decode to raise an error if
  there are non-base64 alphabet characters in the input.

- Issue #10386: Add __all__ to token module; this simplifies importing in
  tokenize module and prevents leaking of private names through ``import *``.

- Issue #4471: Properly shutdown socket in IMAP.shutdown().  Patch by Lorenzo
  M. Catucci.

- Fix IMAP.login() to work properly.

- Issue #9244: multiprocessing pool worker processes could terminate
  unexpectedly if the return value of a task could not be pickled.  Only the
  ``repr`` of such errors are now sent back, wrapped in an
  ``MaybeEncodingError`` exception.

- Issue #9244: The ``apply_async()`` and ``map_async()`` methods of
  ``multiprocessing.Pool`` now accepts a ``error_callback`` argument.  This can
  be a callback with the signature ``callback(exc)``, which will be called if
  the target raises an exception.

- Issue #10022: The dictionary returned by the ``getpeercert()`` method of SSL
  sockets now has additional items such as ``issuer`` and ``notBefore``.

- ``usenetrc`` is now false by default for NNTP objects.

- Issue #1926: Add support for NNTP over SSL on port 563, as well as STARTTLS.
  Patch by Andrew Vant.

- Issue #10335: Add tokenize.open(), detect the file encoding using
  tokenize.detect_encoding() and open it in read only mode.

- Issue #10321: Add support for binary data to smtplib.SMTP.sendmail, and a new
  method send_message to send an email.message.Message object.

- Issue #6011: sysconfig and distutils.sysconfig use the surrogateescape error
  handler to parse the Makefile file.  Avoid a UnicodeDecodeError if the source
  code directory name contains a non-ASCII character and the locale encoding is
  ASCII.

- Issue #10329: The trace module writes reports using the input Python script
  encoding, instead of the locale encoding.  Patch written by Alexander
  Belopolsky.

- Issue #10126: Fix distutils' test_build when Python was built with
  --enable-shared.

- Issue #9281: Prevent race condition with mkdir in distutils.  Patch by
  Arfrever.

- Issue #10229: Fix caching error in gettext.

- Issue #10252: Close file objects in a timely manner in distutils code and
  tests.  Patch by Brian Brazil, completed by Éric Araujo.

- Issue #10180: Pickling file objects is now explicitly forbidden, since
  unpickling them produced nonsensical results.

- Issue #10311: The signal module now restores errno before returning from its
  low-level signal handler.  Patch by Hallvard B Furuseth.

- Issue #10282: Add a ``nntp_implementation`` attribute to NNTP objects.

- Issue #10283: Add a ``group_pattern`` argument to NNTP.list().

- Issue #10155: Add IISCGIHandler to wsgiref.handlers to support IIS CGI
  environment better, and to correct unicode environment values for WSGI 1.0.1.

- Issue #10281: nntplib now returns None for absent fields in the OVER/XOVER
  response, instead of raising an exception.

- wsgiref now implements and validates PEP 3333, rather than an experimental
  extension of PEP 333.  (Note: earlier versions of Python 3.x may have
  incorrectly validated some non-compliant applications as WSGI compliant; if
  your app validates with Python <3.2b1+, but not on this version, it is likely
  the case that your app was not compliant.)

- Issue #10280: NNTP.nntp_version should reflect the highest version advertised
  by the server.

- Issue #10184: Touch directories only once when extracting a tarfile.

- Issue #10199: New package, ``turtledemo`` now contains selected demo scripts
  that were formerly found under Demo/turtle.

- Issue #10265: Close file objects explicitly in sunau.  Patch by Brian Brazil.

- Issue #10266: uu.decode didn't close in_file explicitly when it was given as a
  filename.  Patch by Brian Brazil.

- Issue #10110: Queue objects didn't recognize full queues when the maxsize
  parameter had been reduced.

- Issue #10160: Speed up operator.attrgetter.  Patch by Christos Georgiou.

- logging: Added style option to basicConfig() to allow %, {} or $-formatting.

- Issue #5729: json.dumps() now supports using a string such as '\t' for
  pretty-printing multilevel objects.

- Issue #10253: FileIO leaks a file descriptor when trying to open a file for
  append that isn't seekable.  Patch by Brian Brazil.

- Support context manager protocol for file-like objects returned by mailbox
  ``get_file()`` methods.

- Issue #10246: uu.encode didn't close file objects explicitly when filenames
  were given to it.  Patch by Brian Brazil.

- Issue #10198: fix duplicate header written to wave files when writeframes() is
  called without data.

- Close file objects in modulefinder in a timely manner.

- Close a io.TextIOWrapper object in email.parser in a timely manner.

- Close a file object in distutils.sysconfig in a timely manner.

- Close a file object in pkgutil in a timely manner.

- Issue #10233: Close file objects in a timely manner in the tarfile module and
  its test suite.

- Issue #10093: ResourceWarnings are now issued when files and sockets are
  deallocated without explicit closing.  These warnings are silenced by default,
  except in pydebug mode.

- tarfile.py: Add support for all missing variants of the GNU sparse extensions
  and create files with holes when extracting sparse members.

- Issue #10218: Return timeout status from ``Condition.wait`` in threading.

- Issue #7351: Add ``zipfile.BadZipFile`` spelling of the exception name and
  deprecate the old name ``zipfile.BadZipfile``.

- Issue #5027: The standard ``xml`` namespace is now understood by
  xml.sax.saxutils.XMLGenerator as being bound to
  http://www.w3.org/XML/1998/namespace.  Patch by Troy J. Farrell.

- Issue #5975: Add csv.unix_dialect class.

- Issue #7761: telnetlib.interact failures on Windows fixed.

- logging: Added style option to Formatter to allow %, {} or $-formatting.

- Issue #5178: Added tempfile.TemporaryDirectory class that can be used as a
  context manager.

- Issue #1349106: Generator (and BytesGenerator) flatten method and Header
  encode method now support a 'linesep' argument.

- Issue #5639: Add a *server_hostname* argument to ``SSLContext.wrap_socket`` in
  order to support the TLS SNI extension.  ``HTTPSConnection`` and ``urlopen()``
  also use this argument, so that HTTPS virtual hosts are now supported.

- Issue #10166: Avoid recursion in pstats Stats.add() for many stats items.

- Issue #10163: Skip unreadable registry keys during mimetypes initialization.

- logging: Made StreamHandler terminator configurable.

- logging: Allowed filters to be just callables.

- logging: Added tests for _logRecordClass changes.

- Issue #10092: Properly reset locale in calendar.Locale*Calendar classes.

- logging: Added _logRecordClass, getLogRecordClass, setLogRecordClass to
  increase flexibility of LogRecord creation.

- Issue #5117: Case normalization was needed on ntpath.relpath().  Also fixed
  root directory issue on posixpath.relpath().  (Ported working fixes from
  ntpath.)

- Issue #1343: xml.sax.saxutils.XMLGenerator now has an option
  short_empty_elements to direct it to use self-closing tags when appropriate.

- Issue #9807 (part 1): Expose the ABI flags in sys.abiflags.  Add --abiflags
  switch to python-config for command line access.

- Issue #6098: Don't claim DOM level 3 conformance in minidom.

- Issue #5762: Fix AttributeError raised by ``xml.dom.minidom`` when an empty
  XML namespace attribute is encountered.

- Issue #2830: Add the ``html.escape()`` function, which quotes all problematic
  characters by default.  Deprecate ``cgi.escape()``.

- Issue #9409: Fix the regex to match all kind of filenames, for interactive
  debugging in doctests.

- Issue #9183: ``datetime.timezone(datetime.timedelta(0))`` will now return the
  same instance as ``datetime.timezone.utc``.

- Issue #7523: Add SOCK_CLOEXEC and SOCK_NONBLOCK to the socket module, where
  supported by the system.  Patch by Nikita Vetoshkin.

- Issue #10063: file:// scheme will stop accessing remote hosts via ftp
  protocol. file:// urls had fallback to access remote hosts via ftp. This was
  not correct, change is made to raise a URLError when a remote host is tried to
  access via file:// scheme.

- Issue #1710703: Write structures for an empty ZIP archive when a ZipFile is
  created in modes 'a' or 'w' and then closed without adding any files. Raise
  BadZipfile (rather than IOError) when opening small non-ZIP files.

- Issue #10041: The signature of optional arguments in socket.makefile() didn't
  match that of io.open(), and they also didn't get forwarded properly to
  TextIOWrapper in text mode.  Patch by Kai Zhu.

- Issue #9003: http.client.HTTPSConnection, urllib.request.HTTPSHandler and
  urllib.request.urlopen now take optional arguments to allow for server
  certificate checking, as recommended in public uses of HTTPS.

- Issue #6612: Fix site and sysconfig to catch os.getcwd() error, eg. if the
  current directory was deleted. Patch written by W. Trevor King.

- Issue #3873: Speed up unpickling from file objects that have a peek() method.

- Issue #10075: Add a session_stats() method to SSLContext objects.

- Issue #9948: Fixed problem of losing filename case information.

Extension Modules
-----------------

- Issue #5109: array.array constructor will now use fast code when
  initial data is provided in an array object with correct type.

- Issue #6317: Now winsound.PlaySound only accepts unicode.

- Issue #6317: Now winsound.PlaySound can accept non ascii filename.

- Issue #9377: Use Unicode API for gethostname on Windows.

- Issue #10143: Update "os.pathconf" values.

- Issue #6518: Support context manager protcol for ossaudiodev types.

- Issue #678250: Make mmap flush a noop on ACCESS_READ and ACCESS_COPY.

- Issue #9054: Fix a crash occurring when using the pyexpat module with expat
  version 2.0.1.

- Issue #5355: Provide mappings from Expat error numbers to string descriptions
  and backwards, in order to actually make it possible to analyze error codes
  provided by ExpatError.

- The Unicode database was updated to 6.0.0.

C-API
-----

- Issue #10288: The deprecated family of "char"-handling macros
  (ISLOWER()/ISUPPER()/etc) have now been removed: use Py_ISLOWER() etc instead.

- Issue #9778: Hash values are now always the size of pointers. A new Py_hash_t
  type has been introduced.

Tools/Demos
-----------

- Issue #10117: Tools/scripts/reindent.py now accepts source files that use
  encoding other than ASCII or UTF-8.  Source encoding is preserved when
  reindented code is written to a file.

- Issue #7287: Demo/imputil/knee.py was removed.

Tests
-----

- Issue #3699: Fix test_bigaddrspace and extend it to test bytestrings as well
  as unicode strings.  Initial patch by Sandro Tosi.

- Issue #10294: Remove dead code form test_unicode_file.

- Issue #10123: Don't use non-ascii filenames in test_doctest tests. Add a new
  test specific to unicode (non-ascii name and filename).

Build
-----

- Issue #10268: Add a --enable-loadable-sqlite-extensions option to configure.

- Issue #8852: Allow the socket module to build on OpenSolaris.

- Drop -OPT:Olimit compiler option.

- Issue #10094: Use versioned .so files on GNU/kfreeBSD and the GNU Hurd.

- Accept Oracle Berkeley DB 5.0 and 5.1 as backend for the dbm extension.

- Issue #7473: avoid link errors when building a framework with a different set
  of architectures than the one that is currently installed.


What's New in Python 3.2 Alpha 3?
=================================

*Release date: 09-Oct-2010*

Core and Builtins
-----------------

- Issue #10068: Global objects which have reference cycles with their module's
  dict are now cleared again. This causes issue #7140 to appear again.

- Issue #9738: Document PyErr_SetString() and PyErr_SetFromErrnoWithFilename()
  encodings.

- ast.literal_eval() can now handle negative numbers.  It is also a little more
  liberal in what it accepts without compromising the safety of the evaluation.
  For example, 3j+4 and 3+4+5 are both accepted.

- Issue #10006: type.__abstractmethods__ now raises an AttributeError.  As a
  result metaclasses can now be ABCs (see #9533).

- Issue #8670: ctypes.c_wchar supports non-BMP characters with 32 bits wchar_t.

- Issue #8670: PyUnicode_AsWideChar() and PyUnicode_AsWideCharString() replace
  UTF-16 surrogate pairs by single non-BMP characters for 16 bits Py_UNICODE and
  32 bits wchar_t (eg. Linux in narrow build).

- Issue #10003: Allow handling of SIGBREAK on Windows. Fixes a regression
  introduced by issue #9324.

- Issue #9979: Create function PyUnicode_AsWideCharString().

- Issue #7397: Mention that importlib.import_module() is probably what someone
  really wants to be using in __import__'s docstring.

- Issue #8521: Allow CreateKeyEx, OpenKeyEx, and DeleteKeyEx functions of winreg
  to use named arguments.

- Issue #9930: Remove bogus subtype check that was causing (e.g.)
  float.__rdiv__(2.0, 3) to return NotImplemented instead of the expected 1.5.

- Issue #9808: Implement os.getlogin for Windows. Patch by Jon Anglin.

- Issue #9901: Destroying the GIL in Py_Finalize() can fail if some other
  threads are still running.  Instead, reinitialize the GIL on a second call to
  Py_Initialize().

- All SyntaxErrors now have a column offset and therefore a caret when the error
  is printed.

- Issue #9252: PyImport_Import no longer uses a fromlist hack to return the
  module that was imported, but instead gets the module from sys.modules.

- Issue #9213: The range type_items now provides index() and count() methods, to
  conform to the Sequence ABC.  Patch by Daniel Urban and Daniel Stutzbach.

- Issue #7994: Issue a PendingDeprecationWarning if object.__format__ is called
  with a non-empty format string.  This is an effort to future-proof user
  code. If a derived class does not currently implement __format__ but later
  adds its own __format__, it would most likely break user code that had
  supplied a format string.  This will be changed to a DeprecationWaring in
  Python 3.3 and it will be an error in Python 3.4.

- Issue #9828: Destroy the GIL in Py_Finalize(), so that it gets properly
  re-created on a subsequent call to Py_Initialize().  The problem (a crash)
  wouldn't appear in 3.1 or 2.7 where the GIL's structure is more trivial.

- Issue #9210: Configure option --with-wctype-functions was removed.  Using the
  functions from the libc caused the methods .upper() and lower() to become
  locale aware and created subtly wrong results.

- Issue #9738: PyUnicode_FromFormat() and PyErr_Format() raise an error on a
  non-ASCII byte in the format string.

- Issue #4617: Previously it was illegal to delete a name from the local
  namespace if it occurs as a free variable in a nested block.  This limitation
  of the compiler has been lifted, and a new opcode introduced (DELETE_DEREF).

- Issue #9804: ascii() now always represents unicode surrogate pairs as a single
  ``\UXXXXXXXX``, regardless of whether the character is printable or not.
  Also, the "backslashreplace" error handler now joins surrogate pairs into a
  single character on UCS-2 builds.

- Issue #9757: memoryview objects get a release() method to release the
  underlying buffer (previously this was only done when deallocating the
  memoryview), and gain support for the context management protocol.

- Issue #9797: pystate.c wrongly assumed that zero couldn't be a valid
  thread-local storage key.

Library
-------

- Issue #2236: distutils' mkpath ignored the mode parameter.

- Fix typo in one sdist option (medata-check).

- Issue #9199: Fix incorrect use of distutils.cmd.Command.announce.

- Issue #1718574: Fix options that were supposed to accept arguments but did
  not in build_clib.

- Issue #9437: Fix building C extensions with non-default LDFLAGS.

- Issue #4661: email can now parse bytes input and generate either converted
  7bit output or bytes output.  Email version bumped to 5.1.0.

- Issue #1589: Add ssl.match_hostname(), to help implement server identity
  verification for higher-level protocols.

- Issue #9759: GzipFile now raises ValueError when an operation is attempted
  after the file is closed.  Patch by Jeffrey Finkelstein.

- Issue #9042: Fix interaction of custom translation classes and caching in
  gettext.

- Issue #6706: asyncore.dispatcher now provides a handle_accepted() method
  returning a (sock, addr) pair which is called when a connection has been
  established with a new remote endpoint.  This is supposed to be used as a
  replacement for old handle_accept() and avoids the user to call accept()
  directly.

- Issue #9065: tarfile no longer uses "root" as the default for the uname and
  gname field.

- Issue #8980: Fixed a failure in distutils.command check that was shadowed by
  an environment that does not have docutils.  Patch by Arfrever.

- Issue #1050268: parseaddr now correctly quotes double quote and backslash
  characters that appear inside quoted strings in email addresses.

- Issue #10004: quoprimime no longer generates a traceback when confronted with
  invalid characters after '=' in a Q-encoded word.

- Issue #1491: BaseHTTPServer nows send a ``100 Continue`` response before
  sending a 200 OK for the Expect: 100-continue request header.

- Issue #9360: Cleanup and improvements to the nntplib module.  The API now
  conforms to the philosophy of bytes and unicode separation in Python 3.  A
  test suite has also been added.

- Issue #9962: GzipFile now has the peek() method.

- Issue #9090: When a socket with a timeout fails with EWOULDBLOCK or EAGAIN,
  retry the select() loop instead of bailing out.  This is because select() can
  incorrectly report a socket as ready for reading (for example, if it received
  some data with an invalid checksum).

- Issue #3612: Added new types to ctypes.wintypes. (CHAR and pointers)

- Issue #9950: Fix socket.sendall() crash or misbehaviour when a signal is
  received.  Now sendall() properly calls signal handlers if necessary, and
  retries sending if these returned successfully, including on sockets with a
  timeout.

- Issue #9947: logging: Fixed locking bug in stopListening.

- Issue #9945: logging: Fixed locking bugs in addHandler/removeHandler.

- Issue #9936: Fixed executable lines' search in the trace module.

- Issue #9790: Rework imports necessary for samefile and sameopenfile
  in ntpath.

- Issue #9928: Properly initialize the types exported by the bz2 module.

- Issue #1675951: Allow GzipFile to work with unseekable file objects.  Patch by
  Florian Festi.

- Logging: Added QueueListener class to facilitate logging usage for
  performance-critical threads.

- Issue #9916: Add some missing errno symbols.

- Issue #9877: Expose sysconfig.get_makefile_filename()

- logging: Added hasHandlers() method to Logger and LoggerAdapter.

- Issue #9908: Fix os.stat() on bytes paths under Windows 7.

- Issue #2643: msync() is not called anymore when deallocating an open mmap
  object, only munmap().

- logging: Changed LoggerAdapter implementation internally, to make it easier to
  subclass in a useful way.

- logging: hasHandlers method was added to Logger, and isEnabledFor,
  getEffectiveLevel, hasHandlers and setLevel were added to LoggerAdapter.
  LoggerAdapter was introduced into the unit tests for logging.

- Issue #1686: Fix string.Template when overriding the pattern attribute.

- Issue #9854: SocketIO objects now observe the RawIOBase interface in
  non-blocking mode: they return None when an operation would block (instead of
  raising an exception).

- Issue #1730136: Fix the comparison between a tk.font.Font and an object of
  another kind.

- Issue #9441: logging has better coverage for rotating file handlers.

- Issue #9865: collections.OrderedDict now has a __sizeof__ method.

- Issue #9854: The default read() implementation in io.RawIOBase now handles
  non-blocking readinto() returning None correctly.

- Issue #1552: socket.socketpair() now returns regular socket.socket objects
  supporting the whole socket API (rather than the "raw" _socket.socket
  objects).

- Issue #9853: Fix the signature of SSLSocket.recvfrom() and SSLSocket.sendto()
  to match the corresponding socket methods.

- Issue #9840: Added a decorator to reprlib for wrapping __repr__ methods to make
  them handle recursive calls within the same thread.

- logging: Enhanced HTTPHandler with secure and credentials initializers.

- Issue #767645: Set os.path.supports_unicode_filenames to True on Mac OS X.

- Issue #9837: The read() method of ZipExtFile objects (as returned by
  ZipFile.open()) could return more bytes than requested.

- Issue #9826: OrderedDict.__repr__ can now handle self-referential values:
  d['x'] = d.

- Issue #9825: Using __del__ in the definition of collections.OrderedDict made
  it possible for the user to create self-referencing ordered dictionaries which
  become permanently uncollectable GC garbage.  Reinstated the Python 3.1
  approach of using weakref proxies so that reference cycles never get created
  in the first place.

- Issue #9579, #9580: Fix os.confstr() for value longer than 255 bytes and
  encode the value with filesystem encoding and surrogateescape (instead of
  utf-8 in strict mode) . Patch written by David Watson.

- Issue #9632: Remove sys.setfilesystemencoding() function: use PYTHONFSENCODING
  environment variable to set the filesystem encoding at Python startup.
  sys.setfilesystemencoding() creates inconsistencies because it is unable to
  reencode all filenames in all objects.

- Issue #9410: Various optimizations to the pickle module, leading to speedups
  up to 4x (depending on the benchmark).  Mostly ported from Unladen Swallow;
  initial patch by Alexandre Vassalotti.

- The pprint module now supports printing OrderedDicts in their given order
  (formerly, it would sort the keys).

- Logging: Added QueueHandler class to facilitate logging usage with
  multiprocessing.

- Issue #9707: Rewritten reference implementation of threading.local which is
  friendlier towards reference cycles.  This change is not normally visible
  since an optimized C implementation (_thread._local) is used instead.

- Issue #6394: os.getppid() is now supported on Windows.  Note that it will
  still return the id of the parent process after it has exited.  This process
  id may even have been reused by another unrelated process.

- Issue #9792: In case of connection failure, socket.create_connection() would
  swallow the exception and raise a new one, making it impossible to fetch the
  original errno, or to filter timeout errors.  Now the original error is
  re-raised.

- Issue #9758: When fcntl.ioctl() was called with mutable_flag set to True, and
  the passed buffer was exactly 1024 bytes long, the buffer wouldn't be updated
  back after the system call.  Original patch by Brian Brazil.

- Updates to the random module:

  * Document which parts of the module are guaranteed to stay the same across
    versions and which parts are subject to change.

  * Update the seed() method to use all of the bits in a string instead of just
    the hash value.  This makes better use of the seed value and assures the
    seeding is platform independent.  Issue #7889.

  * Improved the random()-->integer algorithm used in choice(), shuffle(),
    sample(), randrange(), and randint().  Formerly, it used int(n*random())
    which has a slight bias whenever n is not a power of two.  Issue #9025.

  * Improved documentation of arguments to randrange().  Issue #9379.

- collections.OrderedDict now supports a new method for repositioning keys to
  either end.

- Issue #9754: Similarly to assertRaises and assertRaisesRegexp, unittest test
  cases now also have assertWarns and assertWarnsRegexp methods to check that a
  given warning type was triggered by the code under test.

- Issue #5506: BytesIO objects now have a getbuffer() method exporting a view of
  their contents without duplicating them.  The view is both readable and
  writable.

- Issue #7566: Implement os.path.sameopenfile for Windows.

- Issue #9293: I/O streams now raise ``io.UnsupportedOperation`` when an
  unsupported operation is attempted (for example, writing to a file open only
  for reading).

- hashlib has two new constant attributes: algorithms_guaranteed and
  algorithms_avaiable that respectively list the names of hash algorithms
  guaranteed to exist in all Python implementations and the names of hash
  algorithms available in the current process.

- A new package ``concurrent.futures`` as defined by PEP 3148.

C-API
-----

- Add PyErr_SyntaxLocationEx, which supports passing a column offset.

- Issue #9834: Don't segfault in PySequence_GetSlice, PySequence_SetSlice, or
  PySequence_DelSlice when the object doesn't have any mapping operations
  defined.

Tools/Demos
-----------

- Issue #9188: The gdb extension now handles correctly narrow (UCS2) as well as
  wide (UCS4) unicode builds for both the host interpreter (embedded inside gdb)
  and the interpreter under test.

Tests
-----

- Issue #9308: Added tests for importing encoded modules that do not
  depend on specific stdlib modules being encoded in a certain way.

- Issue #1051: Add a script (Lib/test/make_ssl_certs.py) to generate the custom
  certificate and private key files used by SSL-related certs.

- Issue #9978: Wait until subprocess completes initialization. (Win32KillTests
  in test_os)

- Issue #7110: regrtest now sends test failure reports and single-failure
  tracebacks to stderr rather than stdout.

- Issue #9628: fix runtests.sh -x option so more than one test can be excluded.

- Issue #9899: Fix test_tkinter.test_font on various platforms.  Patch by Ned
  Deily.

- Issue #9894: Do not hardcode ENOENT in test_subprocess.

- Issue #9315: Added tests for the trace module.  Patch by Eli Bendersky.

- Issue #9323: Make test.regrtest.__file__ absolute, this was not always the
  case when running profile or trace, for example.

- Issue #9568: Fix test_urllib2_localnet on OS X 10.3.

Build
-----

- Issue #10062: Allow building on platforms which do not have sem_timedwait.

- Issue #10054: Some platforms provide uintptr_t in inttypes.h.  Patch by Akira
  Kitada.

- Issue #10055: Make json C89-compliant in UCS4 mode.

- Issue #9552: Avoid unnecessary rebuild of OpenSSL. (Windows)

- Issue #1633863: Don't ignore $CC under AIX.

- Issue #9810: Compile bzip2 source files in Python's project file directly. It
  used to be built with bzip2's makefile.

- Issue #9848: Stopping trying to build _weakref in setup.py as it is a built-in
  module.

- Issue #9806: python-config now has an ``--extension-suffix`` option that
  outputs the suffix for dynamic libraries including the ABI version name
  defined by PEP 3149.

- Issue #941346: Improve the build process under AIX and allow Python to be
  built as a shared library.  Patch by Sébastien Sablé.

- Issue #4026: Make the fcntl extension build under AIX.  Patch by Sébastien
  Sablé.

- Issue #9701: The MacOSX installer can patch the shell profile to ensure that
  the "bin" directory inside the framework is on the shell's search path. This
  feature now also supports the ZSH shell.


What's New in Python 3.2 Alpha 2?
=================================

*Release date: 05-Sep-2010*

Core and Builtins
-----------------

- Issue #9225: Remove the ROT_FOUR and DUP_TOPX opcode, the latter replaced by
  the new (and simpler) DUP_TOP_TWO.  Performance isn't changed, but our
  bytecode is a bit simplified.  Patch by Demur Rumed.

- Issue #9766: Rename poorly named variables exposed by _warnings to prevent
  confusion with the proper variables names from 'warnings' itself.

- Issue #9212: dict_keys and dict_items now provide the isdisjoint() method, to
  conform to the Set ABC.  Patch by Daniel Urban.

- Issue #9737: Fix a crash when trying to delete a slice or an item from a
  memoryview object.

- Issue #9549: sys.setdefaultencoding() and PyUnicode_SetDefaultEncoding() are
  now removed, since their effect was inexistent in 3.x (the default encoding is
  hardcoded to utf-8 and cannot be changed).

- Issue #7415: PyUnicode_FromEncodedObject() now uses the new buffer API
  properly.  Patch by Stefan Behnel.

- Issue #5553: The Py_LOCAL_INLINE macro now results in inlining on most
  platforms.  Previously, it inlined only when using Microsoft Visual C.

- Issue #9712: Fix tokenize on identifiers that start with non-ascii names.

- Issue #9688: __basicsize__ and __itemsize__ must be accessed as Py_ssize_t.

- Issue #9684: Added a definition for SIZEOF_WCHAR_T to PC/pyconfig.h, to match
  the pyconfig.h generated by configure on other systems.

- Issue #9666: Only catch AttributeError in hasattr(). All other exceptions that
  occur during attribute lookup are now propagated to the caller.

- Issue #8622: Add PYTHONFSENCODING environment variable to override the
  filesystem encoding.

- Issue #5127: The C functions that access the Unicode Database now accept and
  return characters from the full Unicode range, even on narrow unicode builds
  (Py_UNICODE_TOLOWER, Py_UNICODE_ISDECIMAL, and others).  A visible difference
  in Python is that unicodedata.numeric() now returns the correct value for
  large code points, and repr() may consider more characters as printable.

- Issue #9425: Create PyModule_GetFilenameObject() function to get the filename
  as a unicode object, instead of a byte string. Function needed to support
  unencodable filenames. Deprecate PyModule_GetFilename() in favor on the new
  function.

- Issue #8063: Call _PyGILState_Init() earlier in Py_InitializeEx().

- Issue #9612: The set object is now 64-bit clean under Windows.

- Issue #8202: sys.argv[0] is now set to '-m' instead of '-c' when searching for
  the module file to be executed with the -m command line option.

- Issue #9599: Create PySys_FormatStdout() and PySys_FormatStderr() functions to
  write a message formatted by PyUnicode_FromFormatV() to sys.stdout and
  sys.stderr.

- Issue #9542: Create PyUnicode_FSDecoder() function, a ParseTuple converter:
  decode bytes objects to unicode using PyUnicode_DecodeFSDefaultAndSize(); str
  objects are output as-is.

- Issue #9203: Computed gotos are now enabled by default on supported compilers
  (which are detected by the configure script).  They can still be disable
  selectively by specifying --without-computed-gotos.

- Issue #9425: Create PyErr_WarnFormat() function, similar to PyErr_WarnEx() but
  use PyUnicode_FromFormatV() to format the warning message.

- Issue #8530: Prevent stringlib fastsearch from reading beyond the front of an
  array.

- Issue #5319: Print an error if flushing stdout fails at interpreter shutdown.

- Issue #9337: The str() of a float or complex number is now identical to its
  repr().

- Issue #9416: Fix some issues with complex formatting where the output with no
  type specifier failed to match the str output:

    - format(complex(-0.0, 2.0), '-') omitted the real part from the output,
    - format(complex(0.0, 2.0), '-') included a sign and parentheses.

Extension Modules
-----------------

- Issue #8013: time.asctime and time.ctime no longer call system
  asctime and ctime functions.  The year range for time.asctime is now
  1900 through maxint.  The range for time.ctime is the same as for
  time.localtime.  The string produced by these functions is longer
  than 24 characters when year is greater than 9999.

- Issue #6608: time.asctime is now checking struct tm fields its input
  before passing it to the system asctime.  Patch by MunSic Jeong.

- Issue #8734: Avoid crash in msvcrt.get_osfhandle() when an invalid file
  descriptor is provided.  Patch by Pascal Chambon.

- Issue #7736: Release the GIL around calls to opendir() and closedir() in the
  posix module.  Patch by Marcin Bachry.

- Issue #4835: make PyLong_FromSocket_t() and PyLong_AsSocket_t() private to the
  socket module, and fix the width of socket descriptors to be correctly
  detected under 64-bit Windows.

- Issue #1027206: Support IDNA in gethostbyname, gethostbyname_ex, getaddrinfo
  and gethostbyaddr.  getnameinfo is now restricted to numeric addresses as
  input.

- Issue #9214: Set operations on a KeysView or ItemsView in collections now
  correctly return a set.  Patch by Eli Bendersky.

- Issue #5737: Add Solaris-specific mnemonics in the errno module.  Patch by
  Matthew Ahrens.

- Restore GIL in nis_cat in case of error. Decode NIS data to fs encoding, using
  the surrogate error handler.

- Issue #665761: ``functools.reduce()`` will no longer mask exceptions other
  than ``TypeError`` raised by the iterator argument.

- Issue #9570: Use PEP 383 decoding in os.mknod and os.mkfifo.

- Issue #6915: Under Windows, os.listdir() didn't release the Global Interpreter
  Lock around all system calls.  Original patch by Ryan Kelly.

- Issue #8524: Add a detach() method to socket objects, so as to put the socket
  into the closed state without closing the underlying file descriptor.

- Issue #477863: Emit a ResourceWarning at shutdown if gc.garbage is not empty.

- Issue #6869: Fix a refcount problem in the _ctypes extension.

- Issue #5504: ctypes should now work with systems where mmap can't be
  PROT_WRITE and PROT_EXEC.

- Issue #9507: Named tuple repr will now automatically display the right name in
  a tuple subclass.

- Issue #9324: Add parameter validation to signal.signal on Windows in order to
  prevent crashes.

- Issue #9526: Remove some outdated (int) casts that were preventing the array
  module from working correctly with arrays of more than 2**31 elements.

- Fix memory leak in ssl._ssl._test_decode_cert.

- Issue #8065: Fix memory leak in readline module (from failure to free the
  result of history_get_history_state()).

- Issue #9450: Fix memory leak in readline.replace_history_item and
  readline.remove_history_item for readline version >= 5.0.

- Issue #8105: Validate file descriptor passed to mmap.mmap on Windows.

- Issue #8046: Add context manager protocol support and .closed property to mmap
  objects.

Library
-------

- Issue #7451: Improve decoding performance of JSON objects, and reduce the
  memory consumption of said decoded objects when they use the same strings as
  keys.

- Issue #1100562: Fix deep-copying of objects derived from the list and dict
  types.  Patch by Michele Orrù and Björn Lindqvist.

- Issue #9753: Fixed socket.dup, which did not always work correctly on Windows.

- Issue #9421: Made the get<type> methods consistently accept the vars and
  default arguments on all parser classes.

- Issue #7005: Fixed output of None values for RawConfigParser.write and
  ConfigParser.write.

- Issue #8990: array.fromstring() and array.tostring() get renamed to
  frombytes() and tobytes(), respectively, to avoid confusion.  Furthermore,
  array.frombytes(), array.extend() as well as the array.array() constructor now
  accept bytearray objects.  Patch by Thomas Jollans.

- Issue #808164: Fixed socket.close to avoid references to globals, to avoid
  issues when socket.close is called from a __del__ method.

- Issue #9706: ssl module provides a better error handling in various
  circumstances.

- Issue #1868: Eliminate subtle timing issues in thread-local objects by getting
  rid of the cached copy of thread-local attribute dictionary.

- Issue #1512791: In setframerate() in the wave module, non-integral frame rates
  are rounded to the nearest integer.

- Issue #8797: urllib2 does a retry for Basic Authentication failure instead of
  falling into recursion.

- Issue #1194222: email.utils.parsedate now returns RFC2822 compliant four
  character years even if the message contains RFC822 two character years.

- Issue #8750: Fixed MutableSet's methods to correctly handle reflexive
  operations on its self, namely x -= x and x ^= x.

- Issue #9129: smtpd.py is vulnerable to DoS attacks deriving from missing error
  handling when accepting a new connection.

- Issue #9601: ftplib now provides a workaround for non-compliant
  implementations such as IIS shipped with Windows server 2003 returning invalid
  response codes for MKD and PWD commands.

- Issue #658749: asyncore's connect() method now correctly interprets winsock
  errors.

- Issue #9501: Fixed logging regressions in cleanup code.

- Fix functools.total_ordering() to skip methods inherited from object.

- Issue #9572: Importlib should not raise an exception if a directory it thought
  it needed to create was done concurrently by another process.

- Issue #9617: Signals received during a low-level write operation aren't
  ignored by the buffered IO layer anymore.

- Issue #843590: Make "macintosh" an alias to the "mac_roman" encoding.

- Create os.fsdecode(): decode from the filesystem encoding with surrogateescape
  error handler, or strict error handler on Windows.

- Issue #3488: Provide convenient shorthand functions ``gzip.compress`` and
  ``gzip.decompress``.  Original patch by Anand B. Pillai.

- Issue #8807: poplib.POP3_SSL class now accepts a context parameter, which is a
  ssl.SSLContext object allowing bundling SSL configuration options,
  certificates and private keys into a single (potentially long-lived)
  structure.

- Issue #8866: parameters passed to socket.getaddrinfo can now be specified as
  single keyword arguments.

- Address XXX comment in dis.py by having inspect.py prefer to reuse the dis.py
  compiler flag values over defining its own.

- Issue #9147: Added dis.code_info() which is similar to show_code() but returns
  formatted code information in a string rather than displaying on screen.

- Issue #9567: functools.update_wrapper now adds a __wrapped__ attribute
  pointing to the original callable.

- Issue #3445: functools.update_wrapper now tolerates missing attributes on
  wrapped callables.

- Issue #5867: Add abc.abstractclassmethod and abc.abstractstaticmethod.

- Issue #9605: posix.getlogin() decodes the username with file filesystem
  encoding and surrogateescape error handler. Patch written by David Watson.

- Issue #9604: posix.initgroups() encodes the username using the fileystem
  encoding and surrogateescape error handler. Patch written by David Watson.

- Issue #9603: posix.ttyname() and posix.ctermid() decode the terminal name
  using the filesystem encoding and surrogateescape error handler. Patch written
  by David Watson.

- Issue #7647: The posix module now has the ST_RDONLY and ST_NOSUID constants,
  for use with the statvfs() function.  Patch by Adam Jackson.

- Issue #8688: MANIFEST files created by distutils now include a magic comment
  indicating they are generated.  Manually maintained MANIFESTs without this
  marker will not be overwritten or removed.

- Issue #7467: when reading a file from a ZIP archive, its CRC is checked and a
  BadZipfile error is raised if it doesn't match (as used to be the case in
  Python 2.5 and earlier).

- Issue #9550: a BufferedReader could issue an additional read when the original
  read request had been satisfied, which could block indefinitely when the
  underlying raw IO channel was e.g. a socket.  Report and original patch by
  Jason V. Miller.

- Issue #3757: thread-local objects now support cyclic garbage collection.
  Thread-local objects involved in reference cycles will be deallocated timely
  by the cyclic GC, even if the underlying thread is still running.

- Issue #9452: Add read_file, read_string, and read_dict to the configparser
  API; new source attribute to exceptions.

- Issue #6231: Fix xml.etree.ElementInclude to include the tail of the current
  node.

- Issue #8047: Fix the xml.etree serializer to return bytes by default.  Use
  ``encoding="unicode"`` to generate a Unicode string.

- Issue #8280: urllib2's Request method will remove fragments in the url.  This
  is how it is supposed to work, wget and curl do the same.  Previous behavior
  was wrong.

- Issue #6683: For SMTP logins we now try all authentication methods advertised
  by the server.  Many servers are buggy and advertise authentication methods
  they do not support in reality.

- Issue #8814: function annotations (the ``__annotations__`` attribute) are now
  included in the set of attributes copied by default by functools.wraps and
  functools.update_wrapper.  Patch by Terrence Cole.

- Issue #2944: asyncore doesn't handle connection refused correctly.

- Issue #4184: Private attributes on smtpd.SMTPChannel made public and deprecate
  the private attributes. Add tests for smtpd module.

- Issue #3196: email header decoding is now forgiving if an RFC2047 encoded word
  encoded in base64 is lacking padding.

- Issue #9444: Argparse now uses the first element of prefix_chars as the option
  character for the added 'h/help' option if prefix_chars does not contain a
  '-', instead of raising an error.

- Issue #7372: Fix pstats regression when stripping paths from profile data
  generated with the profile module.

- Issue #9428: Fix running scripts with the profile/cProfile modules from the
  command line.

- Issue #7781: Fix restricting stats by entry counts in the pstats interactive
  browser.

- Issue #9209: Do not crash in the pstats interactive browser on invalid regular
  expressions.

- Update collections.OrderedDict to match the implementation in Py2.7 (based on
  lists instead of weakly referenced Link objects).

- Issue #8397: Raise an error when attempting to mix iteration and regular reads
  on a BZ2File object, rather than returning incorrect results.

- Issue #9448: Fix a leak of OS resources (mutexes or semaphores) when
  re-initializing a buffered IO object by calling its ``__init__`` method.

- Issue #1713: Fix os.path.ismount(), which returned true for symbolic links
  across devices.

- Issue #8826: Properly load old-style "expires" attribute in http.cookies.

- Issue #1690103: Fix initial namespace for code run with trace.main().

- Issue #7395: Fix tracebacks in pstats interactive browser.

- Issue #8230: Fix Lib/test/sortperf.py.

- Issue #8620: when a cmd.Cmd() is fed input that reaches EOF without a final
  newline, it no longer truncates the last character of the last command line.

- Issue #5146: Handle UID THREAD command correctly in imaplib.

- Issue #5147: Fix the header generated for cookie files written by
  http.cookiejar.MozillaCookieJar.

- Issue #8198: In pydoc, output all help text to the correct stream when
  sys.stdout is reassigned.

- Issue #7909: Do not touch paths with the special prefixes ``\\.\`` or ``\\?\``
  in ntpath.normpath().

- Issue #1286: Allow using fileinput.FileInput as a context manager.

- Add lru_cache() decorator to the functools module.

Tools/Demos
-----------

- Fix ``Tools/scripts/checkpyc.py`` after PEP 3147.

- Issue #8867: Fix ``Tools/scripts/serve.py`` to work with files containing
  non-ASCII content.

Tests
-----

- Issue #9601: Provide a test case for ftplib.parse257.

- Issue #8857: Provide a test case for socket.getaddrinfo.

- Issue #7564: Skip test_ioctl if another process is attached to /dev/tty.

- Issue #8433: Fix test_curses failure with newer versions of ncurses.

- Issue #9496: Provide a test suite for the rlcompleter module.  Patch by
  Michele Orrù.

- Issue #8687: provide a test suite for sched.py module.

Build
-----

- Issue #1303434: Generate ZIP file containing all PDBs.

- Issue #9193: PEP 3149 is accepted.

- Issue #3101: Helper functions _add_one_to_index_C() and _add_one_to_index_F()
  become _Py_add_one_to_index_C() and _Py_add_one_to_index_F(), respectively.

- Issue #9700: define HAVE_BROKEN_POSIX_SEMAPHORES under AIX 6.x.  Patch by
  Sébastien Sablé.

- Don't run pgen twice when using make -j.


What's New in Python 3.2 Alpha 1?
=================================

*Release date: 01-Aug-2010*

Core and Builtins
-----------------

- Issue #8991: convertbuffer() rejects discontigious buffers.

- Issue #7616: Fix copying of overlapping memoryview slices with the Intel
  compiler.

- Issue #8413: structsequence now subclasses tuple.

- Issue #8271: during the decoding of an invalid UTF-8 byte sequence, only the
  start byte and the continuation byte(s) are now considered invalid, instead of
  the number of bytes specified by the start byte.  E.g.:
  '\xf1\x80AB'.decode('utf-8', 'replace') now returns u'\ufffdAB' and replaces
  with U+FFFD only the start byte ('\xf1') and the continuation byte ('\x80')
  even if '\xf1' is the start byte of a 4-bytes sequence.  Previous versions
  returned a single u'\ufffd'.

- Issue #9011: A negated imaginary literal (e.g., "-7j") now has real part -0.0
  rather than 0.0.  So "-7j" is now exactly equivalent to "-(7j)".

- Be more specific in error messages about positional arguments.

- Issue #8949: "z" format of PyArg_Parse*() functions doesn't accept bytes
  objects, as described in the documentation.

- Issue #6543: Write the traceback in the terminal encoding instead of utf-8.
  Fix the encoding of the modules filename.  Patch written by Amaury Forgeot
  d'Arc.

- Issue #9011: Remove buggy and unnecessary (in 3.x) ST->AST compilation code
  dealing with unary minus applied to a constant.  The removed code was mutating
  the ST, causing a second compilation to fail.

- Issue #850997: mbcs encoding (Windows only) handles errors argument: strict
  mode raises unicode errors.  The encoder only supports "strict" and "replace"
  error handlers, the decoder only supports "strict" and "ignore" error
  handlers.  Patch written by Mark Hammond.

- Issue #8850: Remove "w" and "w#" formats from PyArg_Parse*() functions, use
  "w*" format instead. Add tests for "w*" format.

- Issue #8592: PyArg_Parse*() functions raise a TypeError for "y", "u" and "Z"
  formats if the string contains a null byte/character.  Write unit tests for
  string formats.

- Issue #7490: To facilitate sharing of doctests between 2.x and 3.x test
  suites, the IGNORE_EXCEPTION_DETAIL directive now also ignores the module
  location of the raised exception.

- Issue #8969: On Windows, use mbcs codec in strict mode to encode and decode
  filenames and enable os.fsencode().

- Issue #9058: Remove assertions about INT_MAX in UnicodeDecodeError.

- Issue #8941: Decoding big endian UTF-32 data in UCS-2 builds could crash the
  interpreter with characters outside the Basic Multilingual Plane (higher than
  0x10000).

- Issue #8950: (See also issue #5080).  Py_ArgParse*() functions now raise
  TypeError instead of giving a DeprecationWarning when a float is parsed using
  the 'L' code (for long long).  (All other integer codes already raise
  TypeError in this case.)

- Issue #8922: Normalize the encoding name in PyUnicode_AsEncodedString() to
  enable shortcuts for upper case encoding name. Add also a shortcut for
  "iso-8859-1" in PyUnicode_AsEncodedString() and PyUnicode_Decode().

- Issue #8838: Remove codecs.charbuffer_encode() function.  The buffer protocol
  doesn't support "char buffer" anymore in Python 3.

- Issue #8339: Remove "t#" format of PyArg_Parse*() functions, use "s#" or "s*"
  instead.  codecs.charbuffer_encode() now accepts modifiable buffer objects
  like bytearray.

- Issue #8837: Remove "O?" format of PyArg_Parse*() functions.  The format is no
  used anymore and it was never documented.

- In str.format(), raise a ValueError when indexes to arguments are too large.

- Issue #2844: Make int('42', n) consistently raise ValueError for invalid
  integers n (including n = -909).

- Issue #8188: Introduce a new scheme for computing hashes of numbers (instances
  of int, float, complex, decimal.Decimal and fractions.Fraction) that makes it
  easy to maintain the invariant that hash(x) == hash(y) whenever x and y have
  equal value.

- Issue #8748: Fix two issues with comparisons between complex and integer
  objects.  (1) The comparison could incorrectly return True in some cases
  (2**53+1 == complex(2**53) == 2**53), breaking transitivity of equality.
  (2) The comparison raised an OverflowError for large integers, leading to
  unpredictable exceptions when combining integers and complex objects in sets
  or dicts.

- Issue #8766: Initialize _warnings module before importing the first module.
  Fix a crash if an empty directory called "encodings" exists in sys.path.

- Issue #8589: Decode PYTHONWARNINGS environment variable with the file system
  encoding and surrogateescape error handler instead of the locale encoding to
  be consistent with os.environ.  Add PySys_AddWarnOptionUnicode() function.

- PyObject_Dump() encodes unicode objects to utf8 with backslashreplace (instead
  of strict) error handler to escape surrogates.

- Issue #8715: Create PyUnicode_EncodeFSDefault() function: Encode a Unicode
  object to Py_FileSystemDefaultEncoding with the "surrogateescape" error
  handler, and return bytes.  If Py_FileSystemDefaultEncoding is not set, fall
  back to UTF-8.

- Enable shortcuts for common encodings in PyUnicode_AsEncodedString() for any
  error handler, not only the default error handler (strict).

- Issue #8610: Load file system codec at startup, and display a fatal error on
  failure.  Set the file system encoding to utf-8 (instead of None) if getting
  the locale encoding failed, or if nl_langinfo(CODESET) function is missing.

- PyFile_FromFd() uses PyUnicode_DecodeFSDefault() instead of
  PyUnicode_FromString() to support surrogates in the filename and use the right
  encoding.

- Issue #7507: Quote "!" in pipes.quote(); it is special to some shells.

- PyUnicode_DecodeFSDefaultAndSize() uses surrogateescape error handler.

- Issue #8419: Prevent the dict constructor from accepting non-string keyword
  arguments.

- Issue #8124: PySys_WriteStdout() and PySys_WriteStderr() don't execute
  indirectly Python signal handlers anymore because mywrite() ignores exceptions
  (KeyboardInterrupt).

- Issue #8092: Fix PyUnicode_EncodeUTF8() to support error handler producing
  unicode string (eg. backslashreplace).

- Issue #8485: PyUnicode_FSConverter() doesn't accept byteearray objects
  anymore, you have to convert your bytearray filenames to bytes.

- Issue #7332: Remove the 16KB stack-based buffer in
  PyMarshal_ReadLastObjectFromFile, which doesn't bring any noticeable benefit
  compared to the dynamic memory allocation fallback.  Patch by Charles-François
  Natali.

- Issue #8417: Raise an OverflowError when an integer larger than sys.maxsize is
  passed to bytes or bytearray.

- Issue #7301: Add environment variable $PYTHONWARNINGS.

- Issue #8329: Don't return the same lists from select.select when no fds are
  changed.

- Issue #8259: 1L << (2**31) no longer produces an 'outrageous shift error' on
  64-bit machines.  The shift count for either left or right shift is permitted
  to be up to sys.maxsize.

- Ensure that tokenization of identifiers is not affected by locale.

- Issue #1222585: Added LDCXXSHARED for C++ support. Patch by Arfrever.

- Raise a TypeError when trying to delete a T_STRING_INPLACE struct member.

- Issue #8211: Save/restore CFLAGS around AC_PROG_CC in configure.in, in case it
  is set.

- Issue #8226: sys.setfilesystemencoding() raises a LookupError if the encoding
  is unknown.

- Issue #1583863: A str subclass can now override the __str__ method.

- Issue #8014: Setting a T_UINT or T_PYSSIZET attribute of an object with
  PyMemberDefs could produce an internal error; raise TypeError instead.

- Issue #7845: Rich comparison methods on the complex type now return
  NotImplemented rather than raising a TypeError when comparing with an
  incompatible type; this allows user-defined classes to implement their own
  comparisons with complex.

- Issue #3137: Don't ignore errors at startup, especially a keyboard interrupt
  (SIGINT). If an error occurs while importing the site module, the error is
  printed and Python exits. Initialize the GIL before importing the site module.

- Issue #7173: Generator finalization could invalidate sys.exc_info().

- Issue #7544: Preallocate thread memory before creating the thread to avoid a
  fatal error in low memory condition.

- Issue #7820: The parser tokenizer restores all bytes in the right if the BOM
  check fails.

- Handle errors from looking up __prepare__ correctly.

- Issue #5939: Add additional runtime checking to ensure a valid capsule in
  Modules/_ctypes/callproc.c.

- Issue #7309: Fix unchecked attribute access when converting
  UnicodeEncodeError, UnicodeDecodeError, and UnicodeTranslateError to strings.

- Issue #6902: Fix problem with built-in types format incorrectly with 0
  padding.

- Issue #7988: Fix default alignment to be right aligned for complex.__format__.
  Now it matches other numeric types.

- Issue #5988: Remove deprecated functions PyOS_ascii_formatd,
  PyOS_ascii_strtod, and PyOS_ascii_atof.  Use PyOS_double_to_string and
  PyOS_string_to_double instead.  See issue #5835 for the original deprecations.

- Issue #7385: Fix a crash in `MemoryView_FromObject` when `PyObject_GetBuffer`
  fails.  Patch by Florent Xicluna.

- Issue #7788: Fix an interpreter crash produced by deleting a list slice with
  very large step value.

- Issue #7766: Change sys.getwindowsversion() return value to a named tuple and
  add the additional members returned in an OSVERSIONINFOEX structure.  The new
  members are service_pack_major, service_pack_minor, suite_mask, and
  product_type.

- Issue #7561: Operations on empty bytearrays (such as `int(bytearray())`) could
  crash in many places because of the PyByteArray_AS_STRING() macro returning
  NULL.  The macro now returns a statically allocated empty string instead.

- Issue #6690: Optimize the bytecode for expressions such as `x in {1, 2, 3}`,
  where the right hand operand is a set of constants, by turning the set into a
  frozenset and pre-building it as a constant.  The comparison operation is made
  against the constant instead of building a new set each time it is executed (a
  similar optimization already existed which turned a list of constants into a
  pre-built tuple).  Patch and additional tests by Dave Malcolm.

- Issue #7622: Improve the split(), rsplit(), splitlines() and replace() methods
  of bytes, bytearray and unicode objects by using a common implementation based
  on stringlib's fast search.  Patch by Florent Xicluna.

- Issue #7632: Fix various str -> float conversion bugs present in 2.7 alpha 2,
  including: (1) a serious 'wrong output' bug that could occur for long (> 40
  digit) input strings, (2) a crash in dtoa.c that occurred in debug builds when
  parsing certain long numeric strings corresponding to subnormal values, (3) a
  memory leak for some values large enough to cause overflow, and (4) a number
  of flaws that could lead to incorrectly rounded results.

- The __complex__ method is now looked up on the class of instances to make it
  consistent with other special methods.

- Issue #7462: Implement the stringlib fast search algorithm for the `rfind`,
  `rindex`, `rsplit` and `rpartition` methods.  Patch by Florent Xicluna.

- Issue #7604: Deleting an unset slotted attribute did not raise an
  AttributeError.

- Issue #7534: Fix handling of IEEE specials (infinities, nans, negative zero)
  in ** operator.  The behaviour now conforms to that described in C99 Annex F.

- Issue #1811: improve accuracy and cross-platform consistency for true division
  of integers: the result of a/b is now correctly rounded for ints a and b (at
  least on IEEE 754 platforms), and in particular does not depend on the
  internal representation of an int.

- Issue #6834: replace the implementation for the 'python' and 'pythonw'
  executables on OSX.

  These executables now work properly with the arch(1) command: ``arch -ppc
  python`` will start a universal binary version of python in PPC mode (unlike
  previous releases).

- Issue #7466: Segmentation fault when the garbage collector is called in the
  middle of populating a tuple.  Patch by Florent Xicluna.

- Issue #7419: setlocale() could crash the interpreter on Windows when called
  with invalid values.

- Issue #6077: On Windows, files opened with tempfile.TemporaryFile in "wt+"
  mode would appear truncated on the first '0x1a' byte (aka. Ctrl+Z).

- Issue #7085: Fix crash when importing some extensions in a thread on MacOSX
  10.6.

- Issue #1757126: Fix the cyrillic-asian alias for the ptcp154 encoding.

- Issue #6970: Remove redundant calls when comparing objects that don't
  implement the relevant rich comparison methods.

- Issue #7298: Fixes for range and reversed(range(...)).  Iteration over
  range(a, b, c) incorrectly gave an empty iterator when a, b and c fit in C
  long but the length of the range did not.  Also fix several cases where
  reversed(range(a, b, c)) gave wrong results, and fix a refleak for
  reversed(range(a, b, c)) with large arguments.

- Issue #7244: itertools.izip_longest() no longer ignores exceptions raised
  during the formation of an output tuple.

- Issue #3297: On wide unicode builds, do not split unicode characters into
  surrogates.

- Remove length limitation when constructing a complex number from a string.

- Issue #1087418: Boost performance of bitwise operations for longs.

- Support for AtheOS has been completely removed from the code base. It was
  disabled since Python 3.0.

- Support for several legacy threading libraries has been disabled. These
  libraries are: Mach C threads, SunOS LWP, GNU pth, Irix threads. Support code
  will be entirely removed in 3.3.

- Support for OSF* has been disabled. If nobody stands up, support will be
  removed in 3.3. See <http://bugs.python.org/issue8606>.

- Peephole constant folding had missed UNARY_POSITIVE.

- Issue #1722344: threading._shutdown() is now called in Py_Finalize(), which
  fixes the problem of some exceptions being thrown at shutdown when the
  interpreter is killed. Patch by Adam Olsen.

- Issue #7147: Remove support for compiling Python without complex number
  support.

- Issue #7120: logging: Removed import of multiprocessing which is causing crash
  in GAE.

- Issue #1754094: Improve the stack depth calculation in the compiler.  There
  should be no other effect than a small decrease in memory use.  Patch by
  Christopher Tur Lesniewski-Laas.

- Issue #7065: Fix a crash in bytes.maketrans and bytearray.maketrans when using
  byte values greater than 127.  Patch by Derk Drukker.

- Issue #1571184: The Unicode database contains properties for more characters.
  The tables for code points representing numeric values, white spaces or line
  breaks are now generated from the official Unicode Character Database files,
  and include information from the Unihan.txt file.

- Issue #7019: Raise ValueError when unmarshalling bad long data, instead of
  producing internally inconsistent Python longs.

- Issue #6990: Fix threading.local subclasses leaving old state around after a
  reference cycle GC which could be recycled by new locals.

- Issue #5460: Fix an ambiguity in the grammar.

- Issue #1766304: Improve performance of membership tests on range objects.

- Issue #6713: Improve performance of integer -> string conversions.

- Issue #6846: Fix bug where bytearray.pop() returns negative integers.

- Issue #6750: A text file opened with io.open() could duplicate its output when
  writing from multiple threads at the same time.

- Issue #6707: dir() on an uninitialized module caused a crash.

- Issue #6540: Fixed crash for bytearray.translate() with invalid parameters.

- Issue #6573: set.union() stopped processing inputs if an instance of self
  occurred in the argument chain.

- Issue #6070: On posix platforms import no longer copies the execute bit from
  the .py file to the .pyc file if it is set.

- Issue #1616979: Added the cp720 (Arabic DOS) encoding.

- Issue #6428: Since Python 3.0, the __bool__ method must return a bool object,
  and not an int.  Fix the corresponding error message, and the documentation.

- The deprecated PyCObject has been removed.

- Issue #6347: Include inttypes.h as well as stdint.h in pyport.h.  This fixes a
  build failure on HP-UX: int32_t and uint32_t are defined in inttypes.h instead
  of stdint.h on that platform.

- Issue #6373: Fixed a SystemError when encoding with the latin-1 codec and the
  'surrogateescape' error handler, a string which contains unpaired surrogates.

- Issue #4856: Remove checks for win NT.

- Issue #6687: PyBytes_FromObject() no longer accepts an integer as its argument
  to construct a null-initialized bytes object.

- Issue #1023290: Add from_bytes() and to_bytes() methods to integers.  These
  methods allow the conversion of integers to bytes, and vice-versa.

- Issue #7382: Fix bug in bytes.__getnewargs__ that prevented bytes instances
  from being copied with copy.copy(), and bytes subclasses from being pickled
  properly.

- Code objects now support weak references.

- Issue #7072: isspace(0xa0) is true on Mac OS X.

- Issue #8084: PEP 370 now conforms to system conventions for framework builds
  on MacOS X. That is, "python setup.py install --user" will install into
  "~/Library/Python/2.7" instead of "~/.local".

C-API
-----

- Issue #2443: A new macro, `Py_VA_COPY`, copies the state of the
  variable argument list.  `Py_VA_COPY` is equivalent to C99
  `va_copy`, but available on all python platforms.

- PySlice_GetIndicesEx now clips the step to [-PY_SSIZE_T_MAX, PY_SSIZE_T_MAX]
  instead of [-PY_SSIZE_T_MAX-1, PY_SSIZE_T_MAX].  This makes it safe to do
  "step = -step" when reversing a slice.

- Issue #5753: A new C API function, `PySys_SetArgvEx`, allows embedders of the
  interpreter to set sys.argv without also modifying sys.path.  This helps fix
  `CVE-2008-5983
  <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-5983>`_.

- Add PyArg_ValidateKeywordArguments, which checks if all keyword arguments are
  strings in an efficient manner.

- Issue #8276: PyEval_CallObject() is now only available in macro form.  The
  function declaration, which was kept for backwards compatibility reasons, is
  now removed (the macro was introduced in 1997!).

- Issue #7767: New function PyLong_AsLongLongAndOverflow added, analogous to
  PyLong_AsLongAndOverflow.

- Make PyUnicode_CompareWithASCIIString return not equal if the Python string
  has '\0' at the end.

- Issue #5080: The argument parsing functions PyArg_ParseTuple,
  PyArg_ParseTupleAndKeywords, PyArg_VaParse, PyArg_VaParseTupleAndKeywords and
  PyArg_Parse now raise a DeprecationWarning for float arguments passed with the
  'L' format code.  This will become a TypeError in a future version of Python,
  to match the behaviour of the other integer format codes.

- Issue #7033: Function ``PyErr_NewExceptionWithDoc()`` added.

- Issue #7414: 'C' code wasn't being skipped properly (for keyword arguments) in
  PyArg_ParseTupleAndKeywords.

- Issue #7228: Add '%lld' and '%llu' support to PyString_FromFormat(V) and
  PyErr_Format, on machines with HAVE_LONG_LONG defined.

- Issue #6151: Made PyDescr_COMMON conform to standard C (like PyObject_HEAD in
  PEP 3123).  The PyDescr_TYPE and PyDescr_NAME macros should be should used for
  accessing the d_type and d_name members of structures using PyDescr_COMMON.

- Issue #6405: Remove duplicate type declarations in descrobject.h.

- The code flags for old __future__ features are now available again.

- Issue #5954: Add a PyFrame_GetLineNumber() function to replace most uses of
  PyCode_Addr2Line().

- Issue #5959: Add a PyCode_NewEmpty() function to create a new empty code
  object at a specified file, function, and line number.

- Issue #1419652: Change the first argument to PyImport_AppendInittab() to
  ``const char *`` as the string is stored beyond the call.

- Issue #2422: When compiled with the ``--with-valgrind`` option, the pymalloc
  allocator will be automatically disabled when running under Valgrind.  This
  gives improved memory leak detection when running under Valgrind, while taking
  advantage of pymalloc at other times.

Library
-------

- In pdb, when Ctrl-C is entered while defining commands for a breakpoint, the
  old commands are restored.

- For traceback debugging, the pdb listing now also shows the locations where
  the exception was originally (re)raised, if it differs from the last line
  executed (e.g. in case of finally clauses).

- The pdb command "source" has been added.  It displays the source code for a
  given object, if possible.

- The pdb command "longlist" has been added.  It displays the whole source code
  for the current function.

- Issue #1503502: Make pdb.Pdb easier to subclass by putting message and error
  output into methods.

- Issue #809887: Make the output of pdb's breakpoint deletions more consistent;
  emit a message when a breakpoint is enabled or disabled.

- Issue #5294: Fix the behavior of pdb's "continue" command when called in the
  top-level debugged frame.

- Issue #5727: Restore the ability to use readline when calling into pdb in
  doctests.

- Issue #6719: In pdb, do not stop somewhere in the encodings machinery if the
  source file to be debugged is in a non-builtin encoding.

- Issue #8048: Prevent doctests from failing when sys.displayhook has been
  reassigned.

- Issue #8015: In pdb, do not crash when an empty line is entered as a
  breakpoint command.

- In pdb, allow giving a line number to the "until" command.

- Issue #1437051: For pdb, allow "continue" and related commands in .pdbrc
  files.  Also, add a command-line option "-c" that runs a command as if given
  in .pdbrc.

- Issue #4179: In pdb, allow "list ." as a command to return to the currently
  debugged line.

- Issue #4108: In urllib.robotparser, if there are multiple ``User-agent: *``
  entries, consider the first one.

- Issue #6630: Allow customizing regex flags when subclassing the
  string.Template class.

- Issue #9411: Allow specifying an encoding for config files in the configparser
  module.

- Issue #1682942: Improvements to configparser: support alternate delimiters,
  alternate comment prefixes and empty lines in values.

- Issue #9354: Provide getsockopt() in asyncore's file_wrapper.

- Issue #8966: ctypes: Remove implicit bytes-unicode conversion.

- Issue #9378: python -m pickle <pickle file> will now load and display the
  first object in the pickle file.

- Issue #4770: Restrict binascii module to accept only bytes (as specified).
  And fix the email package to encode to ASCII instead of ``raw-unicode-escape``
  before ASCII-to-binary decoding.

- Issue #9384: ``python -m tkinter`` will now display a simple demo applet.

- The default size of the re module's compiled regular expression cache has been
  increased from 100 to 500 and the cache replacement policy has changed from
  simply clearing the entire cache on overflow to forgetting the least recently
  used cached compiled regular expressions.  This is a performance win for
  applications that use a lot of regular expressions and limits the impact of
  the performance hit anytime the cache is exceeded.

- Issue #7113: Speed up loading in configparser. Patch by Łukasz Langa.

- Issue #9032: XML-RPC client retries the request on EPIPE error.  The EPIPE
  error occurs when the server closes the socket and the client sends a big
  XML-RPC request.

- Issue #4629: getopt raises an error if an argument ends with "=", whereas
  getopt doesn't accept a value (eg. --help= is rejected if getopt uses
  ['help='] long options).

- Issue #7989: Added pure python implementation of the `datetime` module.  The C
  module is renamed to `_datetime` and if available, overrides all classes
  defined in datetime with fast C impementation.  Python implementation is based
  on the original python prototype for the datetime module by Tim Peters with
  minor modifications by the PyPy project.  The test suite now tests `datetime`
  module with and without `_datetime` acceleration using the same test cases.

- Issue #7895: platform.mac_ver() no longer crashes after calling os.fork().

- Issue #9323: Fixed a bug in trace.py that resulted in loosing the name of the
  script being traced.  Patch by Eli Bendersky.

- Issue #9282: Fixed --listfuncs option of trace.py.  Thanks Eli Bendersky for
  the patch.

- Issue #3704: http.cookiejar was not properly handling URLs with a / in the
  parameters.

- Issue #9268: ``pickletools.dis()`` now has an optional *annotate* argument
  which controls printing of opcode descriptions in ``dis()`` output.

- Issue #1555570: email no longer inserts extra blank lines when a \r\n combo
  crosses an 8192 byte boundary.

- Issue #9243: Fix sndhdr module and add unit tests, contributed by James Lee.

- ``ast.literal_eval()`` now allows byte literals.

- Issue #9137: Fix issue in MutableMapping.update, which incorrectly treated
  keyword arguments called 'self' or 'other' specially.

- ``ast.literal_eval()`` now allows set literals.

- Issue #9164: Ensure that sysconfig handles duplicate -arch flags in CFLAGS.

- Issue #7646: The fnmatch pattern cache no longer grows without bound.

- Issue #9136: Fix 'dictionary changed size during iteration' RuntimeError
  produced when profiling the decimal module.  This was due to a dangerous
  iteration over 'locals()' in Context.__init__.

- Fix extreme speed issue in Decimal.pow when the base is an exact power of 10
  and the exponent is tiny (for example, ``Decimal(10) **
  Decimal('1e-999999999')``).

- Issue #9186: Fix math.log1p(-1.0) to raise ValueError, not OverflowError.

- Issue #9130: Fix validation of relative imports in parser module.

- Issue #9128: Fix validation of class decorators in parser module.

- Issue #9094: python -m pickletools will now disassemble pickle files listed in
  the command line arguments.  See output of python -m pickletools -h for more
  details.

- Issue #5468: urlencode to handle bytes type and other encodings in its query
  parameter. Patch by Dan Mahn.

- Issue #7673: Fix security vulnerability (CVE-2010-2089) in the audioop module,
  ensure that the input string length is a multiple of the frame size.

- Issue #6507: Accept source strings in dis.dis().  Original patch by Daniel
  Urban.

- Issue #7829: Clearly document that the dis module is exposing an
  implementation detail that is not stable between Python VMs or releases.

- Issue #6589: cleanup asyncore.socket_map in case smtpd.SMTPServer constructor
  raises an exception.

- Issue #9110: Addition of ContextDecorator to contextlib, for creating APIs
  that act as both context managers and decorators. contextmanager changes to
  use ContextDecorator.

- Implement importlib.abc.SourceLoader and deprecate PyLoader and PyPycLoader
  for removal in Python 3.4.

- Issue #9064: pdb's "up" and "down" commands now accept an optional argument
  giving the number of frames to go.

- Issue #9018: os.path.normcase() now raises a TypeError if the argument is not
  ``str`` or ``bytes``.

- Issue #9075: In the ssl module, remove the setting of a ``debug`` flag on an
  OpenSSL structure.

- Issue #8682: The ssl module now temporary increments the reference count of a
  socket object got through ``PyWeakref_GetObject``, so as to avoid possible
  deallocation while the object is still being used.

- Issue #1368368: FancyURLOpener class changed to throw an Exception on wrong
  password instead of presenting an interactive prompt.  Older behavior can be
  obtained by passing retry=True to http_error_xxx methods of FancyURLOpener.

- Issue #8720: Fix regression caused by fix for #4050 by making getsourcefile
  smart enough to find source files in the linecache.

- Issue #5610: feedparser no longer eats extra characters at the end of a body
  part if the body part ends with a ``\r\n``.

- Issue #8986: math.erfc was incorrectly raising OverflowError for values
  between -27.3 and -30.0 on some platforms.

- Issue #8784: Set tarfile default encoding to 'utf-8' on Windows.

- Issue #8966: If a ctypes structure field is an array of c_char, convert its
  value to bytes instead of str (as done for c_char and c_char_p).

- Issue #8188: Comparisons between Decimal and Fraction objects are now
  permitted, returning a result based on the exact numerical values of the
  operands.  This builds on issue #2531, which allowed Decimal-to-float
  comparisons; all comparisons involving numeric types (bool, int, float,
  complex, Decimal, Fraction) should now act as expected.

- Issue #8897: Fix sunau module, use bytes to write the header. Patch written by
  Thomas Jollans.

- Issue #8899: time.struct_time now has class and attribute docstrings.

- Issue #6470: Drop UNC prefix in FixTk.

- Issue #4768: base64 encoded email body parts were incorrectly stored as binary
  strings.  They are now correctly converted to strings.

- Issue #8833: tarfile created hard link entries with a size field != 0 by
  mistake.

- Charset.body_encode now correctly handles base64 encoding by encoding with the
  output_charset before calling base64mime.encode.  Passes the tests from 2.x
  issue #1368247.

- Issue #8845: sqlite3 Connection objects now have a read-only in_transaction
  attribute that is True iff there are uncommitted changes.

- Issue #1289118: datetime.timedelta objects can now be multiplied by float and
  divided by float and int objects.  Results are rounded to the nearest multiple
  of timedelta.resolution with ties resolved using round-half-to-even method.

- Issue #7150: Raise OverflowError if the result of adding or subtracting
  timedelta from date or datetime falls outside of the MINYEAR:MAXYEAR range.

- Issue #8806: add SSL contexts support to ftplib.

- Issue #4769: Fix main() function of the base64 module, use sys.stdin.buffer
  and sys.stdout.buffer (instead of sys.stdin and sys.stdout) to use the bytes
  API.

- Issue #8770: Now sysconfig displays information when it's called as a script.
  Initial idea by Sridhar Ratnakumar.

- Issue #6662: Fix parsing of malformatted charref (&#bad;), patch written by
  Fredrik Håård.

- Issue #8540: Decimal module: rename the Context._clamp attribute to
  Context.clamp and make it public.  This is useful in creating contexts that
  correspond to the decimal interchange formats specified in IEEE 754.

- Issue #6268: Fix seek() method of codecs.open(), don't read or write the BOM
  twice after seek(0). Fix also reset() method of codecs, UTF-16, UTF-32 and
  StreamWriter classes.

- Issue #3798: sys.exit(message) writes the message to sys.stderr file, instead
  of the C file stderr, to use stderr encoding and error handler.

- Issue #8782: Add a trailing newline in linecache.updatecache to the last line
  of files without one.

- Issue #8729: Return NotImplemented from collections.Mapping.__eq__ when
  comparing to a non-mapping.

- Issue #8774: tabnanny uses the encoding cookie (#coding:...) to use the
  correct encoding.

- Issue #4870: Add an `options` attribute to SSL contexts, as well as several
  ``OP_*`` constants to the `ssl` module.  This allows to selectively disable
  protocol versions, when used in combination with `PROTOCOL_SSLv23`.

- Issue #8759: Fixed user paths in sysconfig for posix and os2 schemes.

- Issue #8663: distutils.log emulates backslashreplace error handler. Fix
  compilation in a non-ASCII directory if stdout encoding is ASCII (eg. if
  stdout is not a TTY).

- Issue #8513: os.get_exec_path() supports b'PATH' key and bytes value.
  subprocess.Popen() and os._execvpe() support bytes program name. Add
  os.supports_bytes_environ flag: True if the native OS type of the environment
  is bytes (eg. False on Windows).

- Issue #8633: tarfile is now able to read and write archives with "raw" binary
  pax headers as described in POSIX.1-2008.

- Issue #1285086: Speed up urllib.parse functions: quote, quote_from_bytes,
  unquote, unquote_to_bytes.

- Issue #8688: Distutils now recalculates MANIFEST everytime.

- Issue #8477: ssl.RAND_egd() and ssl._test_decode_cert() support str with
  surrogates and bytes for the filename.

- Issue #8550: Add first class ``SSLContext`` objects to the ssl module.

- Issue #8681: Make the zlib module's error messages more informative when the
  zlib itself doesn't give any detailed explanation.

- The audioop module now supports sound fragments of length greater than 2**31
  bytes on 64-bit machines, and is PY_SSIZE_T_CLEAN.

- Issue #4972: Add support for the context manager protocol to the ftplib.FTP
  class.

- Issue #8664: In py_compile, create __pycache__ when the compiled path is
  given.

- Issue #8514: Add os.fsencode() function (Unix only): encode a string to bytes
  for use in the file system, environment variables or the command line.

- Issue #8571: Fix an internal error when compressing or decompressing a chunk
  larger than 1GB with the zlib module's compressor and decompressor objects.

- Issue #8603: Support bytes environmental variables on Unix: Add os.environb
  mapping and os.getenvb() function. os.unsetenv() encodes str argument to the
  file system encoding with the surrogateescape error handler (instead of
  utf8/strict) and accepts bytes. posix.environ keys and values are now bytes.

- Issue #8573: asyncore _strerror() function might throw ValueError.

- Issue #8483: asyncore.dispatcher's __getattr__ method produced confusing error
  messages when accessing undefined class attributes because of the cheap
  inheritance with the underlying socket object.  The cheap inheritance has been
  deprecated.

- Issue #4265: shutil.copyfile() was leaking file descriptors when disk fills.
  Patch by Tres Seaver.

- Issue #8390: tarfile uses surrogateescape as the default error handler
  (instead of replace in read mode or strict in write mode).

- Issue #7755: Use an unencumbered audio file for tests.

- Issue #8621: uuid.uuid4() returned the same sequence of values in the parent
  and any children created using ``os.fork`` on MacOS X 10.6.

- Issue #8567: Fix precedence of signals in Decimal module: when a Decimal
  operation raises multiple signals and more than one of those signals is
  trapped, the specification determines the order in which the signals should be
  handled.  In many cases this order wasn't being followed, leading to the wrong
  Python exception being raised.

- Issue #7865: The close() method of ``io`` objects should not swallow
  exceptions raised by the implicit flush().  Also qensure that calling close()
  several times is supported.  Patch by Pascal Chambon.

- Issue #4687: Fix accuracy of garbage collection runtimes displayed with
  gc.DEBUG_STATS.

- Issue #8354: The siginterrupt setting is now preserved for all signals, not
  just SIGCHLD.

- Issue #7192: webbrowser.get("firefox") now works on Mac OS X, as does
  webbrowser.get("safari").

- Issue #8464: tarfile no longer creates files with execute permissions set when
  mode="w|" is used.

- Issue #7834: Fix connect() of Bluetooth L2CAP sockets with recent versions of
  the Linux kernel.  Patch by Yaniv Aknin.

- Issue #8295: Added shutil.unpack_archive.

- Issue #6312: Fixed http HEAD request when the transfer encoding is chunked.
  It should correctly return an empty response now.

- Issue #8546: Reject None given as the buffering argument to _pyio.open.

- Issue #8549: Fix compiling the _ssl extension under AIX.  Patch by
  Sridhar Ratnakumar.

- Issue #6656: fix locale.format_string to handle escaped percents
  and mappings.

- Issue #2302: Fix a race condition in SocketServer.BaseServer.shutdown, where
  the method could block indefinitely if called just before the event loop
  started running.  This also fixes the occasional freezes witnessed in
  test_httpservers.

- Issue #8524: When creating an SSL socket, the timeout value of the original
  socket wasn't retained (instead, a socket with a positive timeout would be
  turned into a non-blocking SSL socket).

- Issue #5103: SSL handshake would ignore the socket timeout and block
  indefinitely if the other end didn't respond.

- The do_handshake() method of SSL objects now adjusts the blocking mode of the
  SSL structure if necessary (as other methods already do).

- Issue #8391: os.execvpe() and os.getenv() supports unicode with surrogates and
  bytes strings for environment keys and values.

- Issue #8467: Pure Python implementation of subprocess encodes the error
  message using surrogatepass error handler to support surrogates in the
  message.

- Issue #8468: bz2.BZ2File() accepts str with surrogates and bytes filenames.

- Issue #8451: Syslog module now uses basename(sys.argv[0]) instead of the
  string "python" as the *ident*.  openlog() arguments are all optional and
  keywords.

- Issue #8108: Fix the unwrap() method of SSL objects when the socket has a
  non-infinite timeout.  Also make that method friendlier with applications
  wanting to continue using the socket in clear-text mode, by disabling
  OpenSSL's internal readahead.  Thanks to Darryl Miles for guidance.

- Issue #8496: make mailcap.lookup() always return a list, rather than an
  iterator.  Patch by Gregory Nofi.

- Issue #8195: Fix a crash in sqlite Connection.create_collation() if the
  collation name contains a surrogate character.

- Issue #8484: Load all ciphers and digest algorithms when initializing the _ssl
  extension, such that verification of some SSL certificates doesn't fail
  because of an "unknown algorithm".

- Issue #6547: Added the ignore_dangling_symlinks option to shutil.copytree.

- Issue #1540112: Now allowing the choice of a copy function in shutil.copytree.

- Issue #4814: timeout parameter is now applied also for connections resulting
  from PORT/EPRT commands.

- Issue #8463: added missing reference to bztar in shutil's documentation.

- Issue #7154: urllib.request can now detect the proxy settings on OSX 10.6 (as
  long as the user didn't specify 'automatic proxy configuration').

- Issue #3817: ftplib.FTP.abort() method now considers 225 a valid response code
  as stated in RFC-959 at chapter 5.4.

- Issue #8394: _ctypes.dlopen() accepts bytes, bytearray and str with
  surrogates.

- Issue #850728: Add a *timeout* parameter to the `acquire()` method of
  `threading.Semaphore` objects.  Original patch by Torsten Landschoff.

- Issue #8322: Add a *ciphers* argument to SSL sockets, so as to change the
  available cipher list.  Helps fix test_ssl with OpenSSL 1.0.0.

- Issue #8393: subprocess accepts bytes, bytearray and str with surrogates for
  the current working directory.

- Issue #7606: XML-RPC traceback stored in X-traceback is now encoded to ASCII
  using backslashreplace error handler.

- Issue #8412: os.system() now accepts bytes, bytearray and str with surrogates.

- Issue #2987: RFC2732 support for urlparse (IPv6 addresses). Patch by Tony
  Locke and Hans Ulrich Niedermann.

- Issue #5277: Fix quote counting when parsing RFC 2231 encoded parameters.

- Issue #7316: The acquire() method of lock objects in the ``threading``
  module now takes an optional timeout argument in seconds.  Timeout support
  relies on the system threading library, so as to avoid a semi-busy wait loop.

- Issue #8383: pickle and pickletools use surrogatepass error handler when
  encoding unicode as utf8 to support lone surrogates and stay compatible with
  Python 2.x and 3.x.

- Issue #7585: difflib context and unified diffs now place a tab between
  filename and date, conforming to the 'standards' they were originally designed
  to follow.  This improves compatibility with patch tools.

- Issue #7472: Fixed typo in email.encoders module; messages using ISO-2022
  character sets will now consistently use a Content-Transfer-Encoding of 7bit
  rather than sometimes being marked as 8bit.

- Issue #8375: test_distutils now checks if the temporary directory are still
  present before it cleans them.

- Issue #8374: Update the internal alias table in the ``locale`` module to
  cover recent locale changes and additions.

- Issue #8321: Give access to OpenSSL version numbers from the `ssl` module,
  using the new attributes `ssl.OPENSSL_VERSION`, `ssl.OPENSSL_VERSION_INFO` and
  `ssl.OPENSSL_VERSION_NUMBER`.

- Add functools.total_ordering() and functools.cmp_to_key().

- Issue #8257: The Decimal construct now accepts a float instance directly,
  converting that float to a Decimal of equal value:

     >>> Decimal(1.1)
     Decimal('1.100000000000000088817841970012523233890533447265625')

- Issue #8294: The Fraction constructor now accepts Decimal and float instances
  directly.

- Issue #7279: Comparisons involving a Decimal signaling NaN now signal
  InvalidOperation instead of returning False.  (Comparisons involving a quiet
  NaN are unchanged.)  Also, Decimal quiet NaNs are now hashable; Decimal
  signaling NaNs remain unhashable.

- Issue #2531: Comparison operations between floats and Decimal instances now
  return a result based on the numeric values of the operands; previously they
  returned an arbitrary result based on the relative ordering of id(float) and
  id(Decimal).  See also issue #8188, which adds Decimal-to-Fraction
  comparisons.

- Added a subtract() method to collections.Counter().

- Issue #8233: When run as a script, py_compile.py optionally takes a single
  argument `-` which tells it to read files to compile from stdin.  Each line is
  read on demand and the named file is compiled immediately.  (Original patch by
  Piotr Ożarowski).

- Backwards incompatible change: Unicode codepoints line tabulation (0x0B) and
  form feed (0x0C) are now considered linebreaks, as specified in Unicode
  Standard Annex #14.  See issue #7643.  http://www.unicode.org/reports/tr14/

- Comparisons using one of <, <=, >, >= between a complex instance and a
  Fractions instance now raise TypeError instead of returning True/False.  This
  makes Fraction <=> complex comparisons consistent with int <=> complex, float
  <=> complex, and complex <=> complex comparisons.

- Issue #8139: ossaudiodev didn't initialize its types properly, therefore some
  methods (such as oss_mixer_device.fileno()) were not available.  Initial patch
  by Bertrand Janin.

- Issue #8205: Remove the "Modules" directory from sys.path when Python is
  running from the build directory (POSIX only).

- Issue #7512: shutil.copystat() could raise an OSError when the filesystem
  didn't support chflags() (for example ZFS under FreeBSD).  The error is now
  silenced.

- Issue #7860: platform.uname now reports the correct 'machine' type when Python
  is running in WOW64 mode on 64 bit Windows.

- Issue #3890, #8222: Fix recv() and recv_into() on non-blocking SSL sockets.
  Also, enable the SSL_MODE_AUTO_RETRY flag on SSL sockets, so that blocking
  reads and writes are always retried by OpenSSL itself.

- Issue #4282: Fix the main function of the profile module for a non-ASCII
  script, open the file in binary mode and not in text mode with the default
  (utf8) encoding.

- Issue #8179: Fix macpath.realpath() on a non-existing path.

- Issue #8024: Update the Unicode database to 5.2.

- Issue #8168: py_compile now handles files with utf-8 BOMS.

- ``tokenize.detect_encoding`` now returns ``'utf-8-sig'`` when a UTF-8 BOM is
  detected.

- Issue #6716/2: Backslash-replace error output in compilall.

- Issue #4961: Inconsistent/wrong result of askyesno function in tkMessageBox
  with Tcl/Tk-8.5.

- Issue #8140: extend compileall to compile single files.  Add -i option.

- Issue #7356: ctypes.util: Make parsing of ldconfig output independent of the
  locale.

- The internals of the subprocess module on POSIX systems have been replaced by
  an extension module (_posixsubprocess) so that the fork()+exec() can be done
  safely without the possibility of deadlock in multithreaded applications.

- subprocess.Popen now has restore_signals and start_new_session features.  The
  default of restore_signals=True is a new behavior compared to earlier Python
  versions.  This means that signals such as SIGPIPE are not ignored by default
  in subprocesses launched by Python (Issue #1652).

- Issue #6472: The xml.etree package is updated to ElementTree 1.3.  The
  cElementTree module is updated too.

- Issue #7774: Set sys.executable to an empty string if argv[0] has been set to
  an non existent program name and Python is unable to retrieve the real program
  name.

- Issue #7880: Fix sysconfig when the python executable is a symbolic link.

- Issue #6509: fix re.sub to work properly when the pattern, the string, and the
  replacement were all bytes.  Patch by Antoine Pitrou.

- The sqlite3 module was updated to pysqlite 2.6.0. This fixes several obscure
  bugs and allows loading SQLite extensions from shared libraries.

- Issue #1054943: Fix ``unicodedata.normalize('NFC', text)`` for the Public
  Review Issue #29 (http://unicode.org/review/pr-29.html).

- Issue #7494: fix a crash in _lsprof (cProfile) after clearing the profiler,
  reset also the pointer to the current pointer context.

- Issue #7232: Add support for the context manager protocol to the TarFile
  class.

- Issue #7250: Fix info leak of os.environ across multi-run uses of
  wsgiref.handlers.CGIHandler.

- Issue #1729305: Fix doctest to handle encode error with "backslashreplace".

- Issue #691291: codecs.open() should not convert end of lines on reading and
  writing.

- Issue #7869: logging: improved diagnostic for format-time errors.

- Issue #7868: logging: added loggerClass attribute to Manager.

- logging: Implemented PEP 391.

- Issue #1537721: Add a writeheader() method to csv.DictWriter.

- Issue #7959: ctypes callback functions are now registered correctly with the
  cycle garbage collector.

- Issue #5801: removed spurious empty lines in wsgiref.

- Issue #6666: fix bug in trace.py that applied the list of directories to be
  ignored only to the first file.  Noted by Bogdan Opanchuk.

- Issue #7597: curses.use_env() can now be called before initscr().  Noted by
  Kan-Ru Chen.

- Issue #7310: fix the __repr__ of os.environ to show the environment variables.

- Issue #7970: email.Generator.flatten now correctly flattens message/rfc822
  messages parsed by email.Parser.HeaderParser.

- Issue #7361: Importlib was not properly checking the number of bytes in
  bytecode file when it was less then 8 bytes.

- Issue #7633: In the decimal module, Context class methods (with the exception
  of canonical and is_canonical) now accept instances of int and long wherever a
  Decimal instance is accepted, and implicitly convert that argument to Decimal.
  Previously only some arguments were converted.

- Issue #7835: shelve should no longer produce mysterious warnings during
  interpreter shutdown.

- Issue #2746: Don't escape ampersands and angle brackets ("&", "<", ">") in XML
  processing instructions and comments.  These raw characters are allowed by the
  XML specification, and are necessary when outputting e.g.  PHP code in a
  processing instruction.  Patch by Neil Muller.

- Issue #6233: ElementTree failed converting unicode characters to XML entities
  when they could't be represented in the requested output encoding.  Patch by
  Jerry Chen.

- Issue #6003: add an argument to ``zipfile.Zipfile.writestr`` to specify the
  compression type.

- Issue #4772: Raise a ValueError when an unknown Bluetooth protocol is
  specified, rather than fall through to AF_PACKET (in the `socket` module).
  Also, raise ValueError rather than TypeError when an unknown TIPC address type
  is specified.  Patch by Brian Curtin.

- Issue #6939: Fix file I/O objects in the `io` module to keep the original file
  position when calling `truncate()`.  It would previously change the file
  position to the given argument, which goes against the tradition of
  ftruncate() and other truncation APIs.  Patch by Pascal Chambon.

- Issue #7610: Reworked implementation of the internal
  ``zipfile.ZipExtFile`` class used to represent files stored inside an
  archive.  The new implementation is significantly faster and can be wrapped in
  a ``io.BufferedReader`` object for more speedups.  It also solves an
  issue where interleaved calls to `read()` and `readline()` give wrong results.
  Patch by Nir Aides.

- Issue #6963: Added "maxtasksperchild" argument to multiprocessing.Pool,
  allowing for a maximum number of tasks within the pool to be completed by the
  worker before that worker is terminated, and a new one created to replace it.

- Issue #7792: Registering non-classes to ABCs raised an obscure error.

- Issue #7785: Don't accept bytes in FileIO.write().

- Removed the functions 'verify' and 'vereq' from Lib/test/support.py.

- Issue #7773: Fix an UnboundLocalError in platform.linux_distribution() when
  the release file is empty.

- Issue #7561: Fix crashes when using bytearray objects with the posix
  module.

- Issue #1670765: Prevent email.generator.Generator from re-wrapping headers in
  multipart/signed MIME parts, which fixes one of the sources of invalid
  modifications to such parts by Generator.

- Issue #7703: Add support for the new buffer API to `binascii.a2bhqx`.  Patch
  by Florent Xicluna, along with some additional tests.

- Issue #7701: Fix crash in binascii.b2a_uu() in debug mode when given a 1-byte
  argument.  Patch by Victor Stinner.

- Issue #3299: Fix possible crash in the _sre module when given bad argument
  values in debug mode.  Patch by Victor Stinner.

- Issue #2846: Add support for gzip.GzipFile reading zero-padded files.  Patch
  by Brian Curtin.

- Issue #7681: Use floor division in appropiate places in the wave module.

- Issue #5372: Drop the reuse of .o files in Distutils' ccompiler (since
  Extension extra options may change the output without changing the .c
  file). Initial patch by Collin Winter.

- Issue #7617: Make sure distutils.unixccompiler.UnixCCompiler recognizes gcc
  when it has a fully qualified configuration prefix. Initial patch by Arfrever.

- Issue #7105: Make WeakKeyDictionary and WeakValueDictionary robust against the
  destruction of weakref'ed objects while iterating.

- Issue #7455: Fix possible crash in cPickle on invalid input.  Patch by Victor
  Stinner.

- Issue #1628205: Socket file objects returned by socket.socket.makefile() now
  properly handles EINTR within the read, readline, write & flush methods.  The
  socket.sendall() method now properly handles interrupted system calls.

- Issue #7471: Improve the performance of GzipFile's buffering mechanism, and
  make it implement the `io.BufferedIOBase` ABC to allow for further speedups by
  wrapping it in an `io.BufferedReader`.  Patch by Nir Aides.

- Issue #3972: http.client.HTTPConnection now accepts an optional source_address
  parameter to allow specifying where your connections come from.

- socket.create_connection now accepts an optional source_address parameter.

- Issue #5511: now zipfile.ZipFile can be used as a context manager.  Initial
  patch by Brian Curtin.

- Issue #7556: Make sure Distutils' msvc9compile reads and writes the MSVC XML
  Manifest file in text mode so string patterns can be used in regular
  expressions.

- Issue #7552: Removed line feed in the base64 Authorization header in the
  Distutils upload command to avoid an error when PyPI reads it.  This occurs on
  long passwords. Initial patch by JP St. Pierre.

- Issue #7231: urllib2 cannot handle https with proxy requiring auth.  Patch by
  Tatsuhiro Tsujikawa.

- Issue #4757: `zlib.compress` and other methods in the zlib module now raise a
  TypeError when given an `str` object (rather than a `bytes`-like object).
  Patch by Victor Stinner and Florent Xicluna.

- Issue #7349: Make methods of file objects in the io module accept None as an
  argument where file-like objects (ie StringIO and BytesIO) accept them to mean
  the same as passing no argument.

- Issue #7357: tarfile no longer suppresses fatal extraction errors by default.

- Issue #5949: added check for correct lineends in input from IMAP server in
  imaplib.

- Add count() and reverse() methods to collections.deque().

- Fix variations of extending deques:  d.extend(d)  d.extendleft(d)  d+=d

- Issue #6986: Fix crash in the JSON C accelerator when called with the wrong
  parameter types.  Patch by Victor Stinner.

- Issue #7457: added a read_pkg_file method to
  distutils.dist.DistributionMetadata.

- logging: Added optional `secure` parameter to SMTPHandler, to enable use of
  TLS with authentication credentials.

- Issue #1923: Fixed the removal of meaningful spaces when PKG-INFO is generated
  in Distutils.  Patch by Stephen Emslie.

- Issue #4120: Drop reference to CRT from manifest when building extensions with
  msvc9compiler.

- Issue #7333: The `posix` module gains an `initgroups()` function providing
  access to the initgroups(3) C library call on Unix systems which implement it.
  Patch by Jean-Paul Calderone.

- Issue #7408: Fixed distutils.tests.sdist so it doesn't check for group
  ownership when the group is not forced, because the group may be different
  from the user's group and inherit from its container when the test is run.

- Issue #4486: When an exception has an explicit cause, do not print its
  implicit context too.  This affects the `traceback` module as well as built-in
  exception printing.

- Issue #1515: Enable use of deepcopy() with instance methods.  Patch by Robert
  Collins.

- Issue #7403: logging: Fixed possible race condition in lock creation.

- Issue #6845: Add restart support for binary upload in ftplib.  The
  `storbinary()` method of FTP and FTP_TLS objects gains an optional `rest`
  argument.  Patch by Pablo Mouzo.

- Issue #5788: `datetime.timedelta` objects get a new `total_seconds()` method
  returning the total number of seconds in the duration.  Patch by Brian
  Quinlan.

- Issue #7133: SSL objects now support the new buffer API.

- Issue #1488943: difflib.Differ() doesn't always add hints for tab characters.

- Issue #6123: tarfile now opens empty archives correctly and consistently
  raises ReadError on empty files.

- Issue #7354: distutils.tests.test_msvc9compiler - dragfullwindows can be 2.

- Issue #5037: Proxy the __bytes__ special method instead to __bytes__ instead
  of __str__.

- Issue #7341: Close the internal file object in the TarFile constructor in case
  of an error.

- Issue #7293: distutils.test_msvc9compiler is fixed to work on any fresh
  Windows box. Help provided by David Bolen.

- Issue #2054: ftplib now provides an FTP_TLS class to do secure FTP using TLS
  or SSL.  Patch by Giampaolo Rodola'.

- Issue #7328: pydoc no longer corrupts sys.path when run with the '-m' switch.

- Issue #4969: The mimetypes module now reads the MIME database from the
  registry under Windows.  Patch by Gabriel Genellina.

- Issue #6816: runpy now provides a run_path function that allows Python code to
  execute file paths that refer to source or compiled Python files as well as
  zipfiles, directories and other valid sys.path entries that contain a
  __main__.py file.  This allows applications that run other Python scripts to
  support the same flexibility as the CPython command line itself.

- Issue #7318: multiprocessing now uses a timeout when it fails to establish a
  connection with another process, rather than looping endlessly.  The default
  timeout is 20 seconds, which should be amply sufficient for local connections.

- Issue #7197: Allow unittest.TextTestRunner objects to be pickled and
  unpickled.  This fixes crashes under Windows when trying to run
  test_multiprocessing in verbose mode.

- Issue #7893: ``unittest.TextTestResult`` is made public and a ``resultclass``
  argument added to the TextTestRunner constructor allowing a different result
  class to be used without having to subclass.

- Issue #7588: ``unittest.TextTestResult.getDescription`` now includes the test
  name in failure reports even if the test has a docstring.

- Issue #3001: Add a C implementation of recursive locks which is used by
  default when instantiating a `threading.RLock` object. This makes recursive
  locks as fast as regular non-recursive locks (previously, they were slower by
  10x to 15x).

- Issue #7282: Fix a memory leak when an RLock was used in a thread other than
  those started through `threading.Thread` (for example, using
  `_thread.start_new_thread()`).

- Issue #7187: Importlib would not silence the IOError raised when trying to
  write new bytecode when it was made read-only.

- Issue #7264: Fix a possible deadlock when deallocating thread-local objects
  which are part of a reference cycle.

- Issue #7211: Allow 64-bit values for the `ident` and `data` fields of kevent
  objects on 64-bit systems.  Patch by Michael Broghton.

- Issue #6896: mailbox.Maildir now invalidates its internal cache each time a
  modification is done through it.  This fixes inconsistencies and test failures
  on systems with slightly bogus mtime behaviour.

- Issue #7246 & Issue #7208: getpass now properly flushes input before reading
  from stdin so that existing input does not confuse it and lead to incorrect
  entry or an IOError.  It also properly flushes it afterwards to avoid the
  terminal echoing the input afterwards on OSes such as Solaris.

- Issue #7233: Fix a number of two-argument Decimal methods to make sure that
  they accept an int or long as the second argument.  Also fix buggy handling of
  large arguments (those with coefficient longer than the current precision) in
  shift and rotate.

- Issue #4750: Store the basename of the original filename in the gzip FNAME
  header as required by RFC 1952.

- Issue #1180: Added a new global option to ignore ~/.pydistutils.cfg in
  Distutils.

- Issue #7218: Fix test_site for win32, the directory comparison was done with
  an uppercase.

- Issue #7205: Fix a possible deadlock when using a BZ2File object from
  several threads at once.

- Issue #7077: logging: SysLogHandler now treats Unicode as per RFC 5424.

- Issue #7099: Decimal.is_normal now returns True for numbers with exponent
  larger than emax.

- Issue #7080: locale.strxfrm() raises a MemoryError on 64-bit non-Windows
  platforms, and assorted locale fixes by Derk Drukker.

- Issue #5833: Fix extra space character in readline completion with the GNU
  readline library version 6.0.

- Issue #6894: Fixed the issue urllib2 doesn't respect "no_proxy" environment.

- Issue #7086: Added TCP support to SysLogHandler, and tidied up some
  anachronisms in the code which were a relic of 1.5.2 compatibility.

- Issue #7082: When falling back to the MIME 'name' parameter, the correct place
  to look for it is the Content-Type header.

- Make tokenize.detect_coding() normalize utf-8 and iso-8859-1 variants like the
  builtin tokenizer.

- Issue #7048: Force Decimal.logb to round its result when that result is too
  large to fit in the current precision.

- Issue #6236, #6348: Fix various failures in the I/O library under AIX and
  other platforms, when using a non-gcc compiler. Patch by Derk Drukker.

- Issue #4606: Passing 'None' if ctypes argtype is set to POINTER(...)  does now
  always result in NULL.

- Issue #5042: Structure sub-subclass does now initialize correctly with base
  class positional arguments.

- Issue #6882: Import uuid creates zombies processes.

- Issue #6635: Fix profiler printing usage message.

- Issue #6856: Add a filter keyword argument to TarFile.add().

- Issue #6888: pdb's alias command was broken when no arguments were given.

- Issue #6857: Default format() alignment should be '>' for Decimal instances.

- Issue #6795: int(Decimal('nan')) now raises ValueError instead of returning
  NaN or raising InvalidContext.  Also, fix infinite recursion in
  long(Decimal('nan')).

- Issue #6850: Fix bug in Decimal._parse_format_specifier for formats with no
  type specifier.

- Issue #6239: ctypes.c_char_p return value must return bytes.

- Issue #6838: Use a list to accumulate the value instead of repeatedly
  concatenating strings in http.client's HTTPResponse._read_chunked providing a
  significant speed increase when downloading large files servend with a
  Transfer-Encoding of 'chunked'.

- Trying to import a submodule from a module that is not a package, ImportError
  should be raised, not AttributeError.

- When the globals past to importlib.__import__() has __package__ set to None,
  fall back to computing what __package__ should be instead of giving up.

- Raise a TypeError when the name of a module to be imported for
  importlib.__import__ is not a string (was raising an AttributeError before).

- Allow the fromlist passed into importlib.__import__ to be any iterable.

- Have importlib raise ImportError if None is found in sys.modules.

- Issue #6054: Do not normalize stored pathnames in tarfile.

- Issue #6794: Fix Decimal.compare_total and Decimal.compare_total_mag: NaN
  payloads are now ordered by integer value rather than lexicographically.

- Issue #1356969: Add missing info methods in tix.HList.

- Issue #1522587: New constants and methods for the tix.Grid widget.

- Issue #1250469: Fix the return value of tix.PanedWindow.panes.

- Issue #1119673: Do not override tkinter.Text methods when creating a
  ScrolledText.

- Issue #6665: Fix fnmatch to properly match filenames with newlines in them.

- Issue #1135: Add the XView and YView mix-ins to avoid duplicating the xview*
  and yview* methods.

- Issue #6629: Fix a data corruption issue in the new I/O library, which could
  occur when writing to a BufferedRandom object (e.g. a file opened in "rb+" or
  "wb+" mode) after having buffered a certain amount of data for reading. This
  bug was not present in the pure Python implementation.

- Issue #6622: Fix "local variable 'secret' referenced before assignment" bug in
  POP3.apop.

- Issue #2715: Remove remnants of Carbon.File from binhex module.

- Issue #6595: The Decimal constructor now allows arbitrary Unicode decimal
  digits in input, as recommended by the standard.  Previously it was restricted
  to accepting [0-9].

- Issue #6106: telnetlib.Telnet.process_rawq doesn't handle default WILL/WONT
  DO/DONT correctly.

- Issue #1424152: Fix for http.client, urllib.request to support SSL while
  working through proxy.  Original patch by Christopher Li, changes made by
  Senthil Kumaran.

- Add importlib.abc.ExecutionLoader to represent the PEP 302 protocol for
  loaders that allow for modules to be executed. Both importlib.abc.PyLoader and
  PyPycLoader inherit from this class and provide implementations in relation to
  other methods required by the ABCs.

- importlib.abc.PyLoader did not inherit from importlib.abc.ResourceLoader like
  the documentation said it did even though the code in PyLoader relied on the
  abstract method required by ResourceLoader.

- Issue #6431: Make Fraction type return NotImplemented when it doesn't know how
  to handle a comparison without loss of precision.  Also add correct handling
  of infinities and nans for comparisons with float.

- Issue #6415: Fixed warnings.warn segfault on bad formatted string.

- Issue #6358: The exit status of a command started with os.popen() was reported
  differently than it did with python 2.x.

- Issue #6323: The pdb debugger did not exit when running a script with a syntax
  error.

- Issue #3392: The subprocess communicate() method no longer fails in select()
  when file descriptors are large; communicate() now uses poll() when possible.

- Issue #6369: Fix an RLE decompression bug in the binhex module.

- Issue #6344: Fixed a crash of mmap.read() when passed a negative argument.

- The deprecated function string.maketrans has been removed.

- Issue #4005: Fixed a crash of pydoc when there was a zip file present in
  sys.path.

- Issue #6218: io.StringIO and io.BytesIO instances are now picklable.

- The os.get_exec_path() function to return the list of directories that will be
  searched for an executable when launching a subprocess was added.

- Issue #7481: When a threading.Thread failed to start it would leave the
  instance stuck in initial state and present in threading.enumerate().

- Issue #1068268: The subprocess module now handles EINTR in internal os.waitpid
  and os.read system calls where appropriate.

- Issue #6729: Added ctypes.c_ssize_t to represent ssize_t.

- Issue #6247: The argparse module has been added to the standard library.

- Issue #8235: _socket: Add the constant ``SO_SETFIB``.  SO_SETFIB is a socket
  option available on FreeBSD 7.1 and newer.

- Issue #9315: Fix for the trace module to record correct class name
  for tracing methods.

Extension Modules
-----------------

- Issue #9959: Tweak formula used for computing math.log of an integer,
  making it marginally more accurate for exact powers of 2.

- Issue #9422: Fix memory leak when re-initializing a struct.Struct object.

- Issue #7900: The getgroups(2) system call on MacOSX behaves rather oddly
  compared to other unix systems. In particular, os.getgroups() does not reflect
  any changes made using os.setgroups() but basicly always returns the same
  information as the id command. os.getgroups() can now return more than 16
  groups on MacOSX.

- Issue #6095: Make directory argument to os.listdir optional.

- Issue #9277: Fix bug in struct.pack for bools in standard mode (e.g.,
  struct.pack('>?')): if conversion to bool raised an exception then that
  exception wasn't properly propagated on machines where char is unsigned.

- Issue #5180: Fixed a bug that prevented loading 2.x pickles in 3.x python when
  they contain instances of old-style classes.

- Issue #9165: Add new functions math.isfinite and cmath.isfinite, to accompany
  existing isinf and isnan functions.

- Issue #1578269: Implement os.symlink for Windows 6.0+.  Patch by Jason
  R. Coombs.

- In struct.pack, correctly propogate exceptions from computing the truth of an
  object in the '?' format.

- Issue #9000: datetime.timezone objects now have eval-friendly repr.

- In the math module, correctly lookup __trunc__, __ceil__, and __floor__ as
  special methods.

- Issue #9005: Prevent utctimetuple() from producing year 0 or year 10,000.
  Prior to this change, timezone adjustment in utctimetuple() could produce
  tm_year value of 0 or 10,000.  Now an OverflowError is raised in these edge
  cases.

- Issue #6641: The ``datetime.strptime`` method now supports the ``%z``
  directive.  When the ``%z`` directive is present in the format string, an
  aware ``datetime`` object is returned with ``tzinfo`` bound to a
  ``datetime.timezone`` instance constructed from the parsed offset.  If both
  ``%z`` and ``%Z`` are present, the data in ``%Z`` field is used for timezone
  name, but ``%Z`` data without ``%z`` is discarded.

- Issue #5094: The ``datetime`` module now has a simple concrete class
  implementing ``datetime.tzinfo`` interface.  Instances of the new class,
  ``datetime.timezone``, return fixed name and UTC offset from their
  ``tzname(dt)`` and ``utcoffset(dt)`` methods.  The ``dst(dt)`` method always
  returns ``None``.  A class attribute, ``utc`` contains an instance
  representing the UTC timezone.  Original patch by Rafe Kaplan.

- Issue #8973: Add __all__ to struct module; this ensures that help(struct)
  includes documentation for the struct.Struct class.

- Issue #3129: Trailing digits in struct format string are no longer ignored.
  For example, "1" or "ilib123" are now invalid formats and cause
  ``struct.error`` to be raised.  Patch by Caleb Deveraux.

- Issue #7384: If the system readline library is linked against ncurses, the
  curses module must be linked against ncurses as well. Otherwise it is not safe
  to load both the readline and curses modules in an application.

- Issue #2810: Fix cases where the Windows registry API returns ERROR_MORE_DATA,
  requiring a re-try in order to get the complete result.

- Issue #8692: Optimize math.factorial: replace the previous naive algorithm
  with an improved 'binary-split' algorithm that uses fewer multiplications and
  allows many of the multiplications to be performed using plain C integer
  arithmetic instead of PyLong arithmetic.  Also uses a lookup table for small
  arguments.

- Issue #8674: Fixed a number of incorrect or undefined-behaviour-inducing
  overflow checks in the audioop module.

- Issue #8644: The accuracy of td.total_seconds() has been improved (by
  calculating with integer arithmetic instead of float arithmetic internally):
  the result is now always correctly rounded, and is equivalent to ``td /
  timedelta(seconds=1)``.

- Issue #2706: Allow division of a timedelta by another timedelta: timedelta /
  timedelta, timedelta % timedelta, timedelta // timedelta and divmod(timedelta,
  timedelta) are all supported.

- Issue #8314: Fix unsigned long long bug in libffi on Sparc v8.

- Issue #8300: When passing a non-integer argument to struct.pack with any
  integer format code, struct.pack first attempts to convert the non-integer
  using its __index__ method.  If that method is non-existent or raises
  TypeError it goes on to try the __int__ method, as described below.

- Issue #8142: Update libffi to the 3.0.9 release.

- Issue #6949: Allow the _dbm extension to be built with db 4.8.x.

- Issue #6544: Fix a reference leak in the kqueue implementation's error
  handling.

- Stop providing crtassem.h symbols when compiling with Visual Studio 2010, as
  msvcr100.dll is not a platform assembly anymore.

- Issue #6508: Add posix.{getresuid,getresgid,setresuid,setresgid}.

- Issue #7078: Set struct.__doc__ from _struct.__doc__.

- Issue #3366: Add erf, erfc, expm1, gamma, lgamma functions to math module.

- Issue #6877: It is now possible to link the readline extension to the libedit
  readline emulation on OSX 10.5 or later.

- Issue #6848: Fix curses module build failure on OS X 10.6.

- Fix a segfault that could be triggered by expat with specially formed input.

- Issue #6561: '\d' in a regex now matches only characters with Unicode category
  'Nd' (Number, Decimal Digit).  Previously it also matched characters with
  category 'No'.

- Issue #4509: Array objects are no longer modified after an operation failing
  due to the resize restriction in-place when the object has exported buffers.

- Issue #2389: Array objects are now pickled in a portable manner.

- Expat: Fix DoS via XML document with malformed UTF-8 sequences
  (CVE_2009_3560).

- Issue #7242: On Solaris 9 and earlier calling os.fork() from within a thread
  could raise an incorrect RuntimeError about not holding the import lock.  The
  import lock is now reinitialized after fork.

- Issue #7999: os.setreuid() and os.setregid() would refuse to accept a -1
  parameter on some platforms such as OS X.

- Build the ossaudio extension on GNU/kFreeBSD.

- Issue #7347: winreg: Add CreateKeyEx and DeleteKeyEx, as well as fix a bug in
  the return value of QueryReflectionKey.

- Issue #7567: PyCurses_setupterm: Don't call ``setupterm`` twice.

Build
-----

- Use OpenSSL 1.0.0a on Windows.

- Issue #9280: Make sharedinstall depend on sharedmods.

- Issue #9189: Make a user-specified CFLAGS, CPPFLAGS, or LDFLAGS setting
  override the configure and makefile defaults, without deleting options the
  user didn't intend to override.  Developers should no longer need to specify
  OPT or EXTRA_CFLAGS, although those variables are still present for
  backward-compatibility.

- Issue #8854: Fix finding Visual Studio 2008 on Windows x64.

- Issue #1759169, #8864: Drop _XOPEN_SOURCE on Solaris, define it for
  multiprocessing only.

- Issue #8625: Turn off optimization in --with-pydebug builds with gcc.
  (Optimization was unintentionally turned on in gcc --with-pydebug builds as a
  result of the issue #1628484 fix, combined with autoconf's strange choice of
  default CFLAGS produced by AC_PROG_CC for gcc.)

- Issue #3646: It is now easily possible to install a Python framework into your
  home directory on MacOSX, see Mac/README for more information.

- Issue #3928: os.mknod() now available in Solaris, also.

- Issue #3326: Build Python without -fno-strict-aliasing when the gcc does not
  give false warnings.

- Issue #1628484: The Makefile doesn't ignore the CFLAGS environment variable
  anymore.  It also forwards the LDFLAGS settings to the linker when building a
  shared library.

- Issue #6716: Quote -x arguments of compileall in MSI installer.  Exclude 2to3
  tests from compileall.

- Issue #3920, #7903: Define _BSD_SOURCE on OpenBSD 4.4 through 4.9.

- Issue #7632: When Py_USING_MEMORY_DEBUGGER is defined, disable the private
  memory allocation scheme in dtoa.c and use PyMem_Malloc and PyMem_Free
  instead.  Also disable caching of powers of 5.

- Issue #6491: Allow --with-dbmliborder to specify that no dbms will be built.

- Issue #6943: Use pkg-config to find the libffi headers when the
  --with-system-ffi flag is used.

- Issue #7609: Add a --with-system-expat option that causes the system's expat
  library to be used for the pyexpat module instead of the one included with
  Python.

- Issue #7589: Only build the nis module when the correct header files are
  found.

- Switch to OpenSSL 0.9.8l and sqlite 3.6.21 on Windows.

- Issue #5792: Extend the short float repr support to x86 systems using
  icc or suncc.

- Issue #6603: Change READ_TIMESTAMP macro in ceval.c so that it compiles
  correctly under gcc on x86-64.  This fixes a reported problem with the
  --with-tsc build on x86-64.

- Issue #6802: Fix build issues on MacOSX 10.6.

- Issue #6244: Allow detect_tkinter to look for Tcl/Tk 8.6.

- Issue #4601: 'make install' did not set the appropriate permissions on
  directories.

- Issue #5390: Add uninstall icon independent of whether file extensions are
  installed.

- Issue #7541: When using ``python-config`` with a framework install the
  compiler might use the wrong library.

- python-config now supports multiple options on the same command line.

- Issue #8509: Fix quoting in help strings and code snippets in configure.in.

- Issue #8510: Update to autoconf2.65.

Documentation
-------------

- Issue #9817: Add expat COPYING file; add expat, libffi and expat licenses
  to Doc/license.rst.

- Issue #9524: Document that two CTRL* signals are meant for use only
  with os.kill.

- Issue #9255: Document that the 'test' package is meant for internal Python use
  only.

- A small WSGI server was added as Tools/scripts/serve.py, and is used to
  implement a local documentation server via 'make serve' in the doc directory.

- Updating `Using Python` documentation to include description of CPython's -J
  and -X options.

- Document that importing a module that has None in sys.modules triggers an
  ImportError.

- Issue #6556: Fixed the Distutils configuration files location explanation for
  Windows.

- Update python manual page (options -B, -O0, -s, environment variables
  PYTHONDONTWRITEBYTECODE, PYTHONNOUSERSITE).

- Issue #8909: Added the size of the bitmap used in the installer created by
  distutils' bdist_wininst. Patch by Anatoly Techtonik.

Tests
-----

- Issue #9251: test_threaded_import didn't fail when run through regrtest if the
  import lock was disabled.

- Issue #8605: Skip test_gdb if Python is compiled with optimizations.

- Issue #7449: Skip test_socketserver if threading support is disabled.

- Issue #8672: Add a zlib test ensuring that an incomplete stream can be handled
  by a decompressor object without errors (it returns incomplete uncompressed
  data).

- Issue #8533: regrtest uses backslashreplace error handler for stdout to avoid
  UnicodeEncodeError (write non-ASCII character to stdout using ASCII encoding).

- Issue #8576: Remove use of find_unused_port() in test_smtplib and
  test_multiprocessing.  Patch by Paul Moore.

- Issue #7449: Fix many tests to support Python compiled without thread
  support. Patches written by Jerry Seutter.

- Issue #8108: test_ftplib's non-blocking SSL server now has proper handling of
  SSL shutdowns.

- Issues #8279, #8330, #8437, #8480, #8495: Fix test_gdb failures, patch written
  by Dave Malcolm.

- Issue #3864: Skip three test_signal tests on freebsd6 because they fail if any
  thread was previously started, most likely due to a platform bug.

- Issue #8193: Fix test_zlib failure with zlib 1.2.4.

- Issue #8248: Add some tests for the bool type.  Patch by Gregory Nofi.

- Issue #8263: Now regrtest.py will report a failure if it receives a
  KeyboardInterrupt (SIGINT).

- Issue #8180 and #8207: Fix test_pep277 on OS X and add more tests for special
  Unicode normalization cases.

- Issue #7783: test.support.open_urlresource invalidates the outdated files from
  the local cache.

- Issue #7849: Now the utility ``check_warnings`` verifies if the warnings are
  effectively raised.

- The four path modules (genericpath, macpath, ntpath, posixpath) share a common
  TestCase for some tests: test_genericpath.CommonTest.

- Print platform information when running the whole test suite, or using the
  --verbose flag.

- Issue #767675: enable test_pep277 on POSIX platforms with Unicode-friendly
  filesystem encoding.

- Issue #6292: for the moment at least, the test suite runs cleanly if python is
  run with the -OO flag.  Tests requiring docstrings are skipped.

- Issue #7712: test.support gained a new `temp_cwd` context manager which is now
  also used by regrtest to run all the tests in a temporary directory.  The
  original CWD is saved in `support.SAVEDCWD`.  Thanks to Florent Xicluna who
  helped with the patch.

- Issue #7924: Fix an intermittent 'XXX undetected error' failure in test_capi
  (only seen so far on platforms where the curses module wasn't built), due to
  an uncleared exception.

- Issue #7728: test_timeout was changed to use support.bind_port instead of a
  hard coded port.

- Issue #7376: Instead of running a self-test (which was failing) when called
  with no arguments, doctest.py now gives a usage message.

- Issue #7396: fix regrtest -s, which was broken by the -j enhancement.

- Issue #7498: test_multiprocessing now uses test.support.find_unused_port
  instead of a hardcoded port number in test_rapid_restart.

- Issue #7431: Use TESTFN in test_linecache instead of trying to create a file
  in the Lib/test directory, which might be read-only for the user running the
  tests.

- Issue #7324: Add a sanity check to regrtest argument parsing to catch the case
  of an option with no handler.

- Issue #7312: Add a -F flag to run the selected tests in a loop until a test
  fails.  Can be combined with -j.

- Issue #6551: test_zipimport could import and then destroy some modules of the
  encodings package, which would make other tests fail further down the road
  because the internally cached encoders and decoders would point to empty
  global variables.

- Issue #7295: Do not use a hardcoded file name in test_tarfile.

- Issue #7270: Add some dedicated unit tests for multi-thread synchronization
  primitives such as Lock, RLock, Condition, Event and Semaphore.

- Issue #7248 (part 2): Use a unique temporary directory for importlib source
  tests instead of tempfile.tempdir. This prevents the tests from sharing state
  between concurrent executions on the same system.

- Issue #7248: In importlib.test.source.util a try/finally block did not make
  sure that some referenced objects actually were created in the block before
  calling methods on the object.

- Issue #7222: Make thread "reaping" more reliable so that reference
  leak-chasing test runs give sensible results.  The previous method of reaping
  threads could return successfully while some Thread objects were still
  referenced.  This also introduces a new private function:
  ``_thread._count()``.

- Issue #7151: Fixed regrtest -j so that output to stderr from a test no longer
  runs the risk of causing the worker thread to fail.

- Issue #7055: test___all__ now greedily detects all modules which have an
  __all__ attribute, rather than using a hardcoded and incomplete list.

- Issue #7058: Added save/restore for things like sys.argv and cwd to
  runtest_inner in regrtest, with warnings if the called test modifies them, and
  a new section in the summary report at the end.

- Issue #7042: Fix test_signal (test_itimer_virtual) failure on OS X 10.6.

- Fixed tests in importlib.test.source.test_abc_loader that were masking the
  proper exceptions that should be raised for missing or improper code object
  bytecode.

- Removed importlib's custom test discovery code and switched to
  unittest.TestLoader.discover().

Tools/Demos
-----------

- Issue #5464, #8974: Implement plural forms in msgfmt.py.

- iobench (a file I/O benchmark) and ccbench (a concurrency benchmark) were
  added to the `Tools/` directory.  They were previously living in the sandbox.


What's New in Python 3.1?
=========================

*Release date: 27-June-2009*

Core and Builtins
-----------------

- Issue #6334: Fix bug in range length calculation for ranges with
  large arguments.

- Issue #6329: Fixed iteration for memoryview objects (it was being blocked
  because it wasn't recognized as a sequence).

Library
-------

- Issue #6126: Fixed pdb command-line usage.

- Issue #6314: logging: performs extra checks on the "level" argument.

- Issue #6274: Fixed possible file descriptors leak in subprocess.py

- Accessing io.StringIO.buffer now raises an AttributeError instead of
  io.UnsupportedOperation.

- Issue #6271: mmap tried to close invalid file handle (-1) when anonymous.
  (On Unix)

- Issue #1202: zipfile module would cause a struct.error when attempting to
  store files with a CRC32 > 2**31-1.

Extension Modules
-----------------

- Issue #5590: Remove unused global variable in pyexpat extension.


What's New in Python 3.1 Release Candidate 2?
=============================================

*Release date: 13-June-2009*

Core and Builtins
-----------------

- Fixed SystemError triggered by "range([], 1, -1)".

- Issue #5924: On Windows, a large PYTHONPATH environment variable
  (more than 255 characters) would be completely ignored.

- Issue #4547: When debugging a very large function, it was not always
  possible to update the lineno attribute of the current frame.

- Issue #5330: C functions called with keyword arguments were not reported by
  the various profiling modules (profile, cProfile). Patch by Hagen Fürstenau.

Library
-------

- Issue #6438: Fixed distutils.cygwinccompiler.get_versions : the regular
  expression string pattern was trying to match against a bytes returned by
  Popen. Tested under win32 to build the py-postgresql project.

- Issue #6258: Support AMD64 in bdist_msi.

- Issue #6195: fixed doctest to no longer try to read 'source' data from
  binary files.

- Issue #5262: Fixed bug in next rollover time computation in
  TimedRotatingFileHandler.

- Issue #6217: The C implementation of io.TextIOWrapper didn't include the
  errors property.  Additionally, the errors and encoding properties of StringIO
  are always None now.

- Issue #6137: The pickle module now translates module names when loading
  or dumping pickles with a 2.x-compatible protocol, in order to make data
  sharing and migration easier. This behaviour can be disabled using the
  new `fix_imports` optional argument.

- Removed the ipaddr module.

- Issue #3613: base64.{encode,decode}string are now called
  base64.{encode,decode}bytes which reflects what type they accept and return.
  The old names are still there as deprecated aliases.

- Issue #5767: Remove sgmlop support from xmlrpc.client.

- Issue #6150: Fix test_unicode on wide-unicode builds.

- Issue #6149: Fix initialization of WeakValueDictionary objects from non-empty
  parameters.

Windows
-------

- Issue #6221: Delete test registry key before running the test.

- Issue #6158: Package Sine-1000Hz-300ms.aif in MSI file.

C-API
-----

- Issue #5735: Python compiled with --with-pydebug should throw an
  ImportError when trying to import modules compiled without
  --with-pydebug, and vice-versa.


Build
-----

- Issue #6154: Make sure the intl library is added to LIBS if needed. Also
  added LIBS to OS X framework builds.

- Issue #5809: Specifying both --enable-framework and --enable-shared is
  an error. Configure now explicity tells you about this.



What's New in Python 3.1 release candidate 1?
=============================================

*Release date: 2009-05-30*

Core and Builtins
-----------------

- Issue #6097: Escape UTF-8 surrogates resulting from mbstocs conversion
  of the command line.

- Issue #6012: Add cleanup support to O& argument parsing.

- Issue #6089: Fixed str.format with certain invalid field specifiers
  that would raise SystemError.

- Issue #5982: staticmethod and classmethod now expose the wrapped
  function with __func__.

- Added support for multiple context managers in the same with-statement.
  Deprecated contextlib.nested() which is no longer needed.

- Issue #5829: complex("1e500") no longer raises OverflowError.  This
  makes it consistent with float("1e500") and interpretation of real
  and imaginary literals.

- Issue #3527: Removed Py_WIN_WIDE_FILENAMES which is not used any more.

- Issue #5994: the marshal module now has docstrings.

- Issue #5981: Fix three minor inf/nan issues in float.fromhex:
  (1) inf and nan strings with trailing whitespace were incorrectly
  rejected;  (2) parsing of strings representing infinities and nans
  was locale aware; and (3) the interpretation of fromhex('-nan')
  didn't match that of float('-nan').

Library
-------

- Issue #4859: Implement PEP 383 for pwd, spwd, and grp.

- smtplib 'login' and 'cram-md5' login are also fixed (see Issue #5259).

- Issue #6121: pydoc now ignores leading and trailing spaces in the
  argument to the 'help' function.

- Issue #6118: urllib.parse.quote_plus ignored the encoding and errors
  arguments for strings with a space in them.

- collections.namedtuple() was not working with the following field
  names:  cls, self, tuple, itemgetter, and property.

- In unittest, using a skipping decorator on a class is now equivalent to
  skipping every test on the class.  The ClassTestSuite class has been removed.

- Issue #6050: Don't fail extracting a directory from a zipfile if
  the directory already exists.

- Issue #1309352: fcntl now converts its third arguments to a C `long` rather
  than an int, which makes some operations possible under 64-bit Linux (e.g.
  DN_MULTISHOT with F_NOTIFY).

- Issue #5761: Add the name of the underlying file to the repr() of various
  IO objects.

- Issue #5259: smtplib plain auth login no longer gives a traceback.  Fix
  by Musashi Tamura, tests by Marcin Bachry.

- Issue #1983: Fix functions taking or returning a process identifier to use
  the dedicated C type ``pid_t`` instead of a C ``int``. Some platforms have
  a process identifier type wider than the standard C integer type.

- Issue #4066: smtplib.SMTP_SSL._get_socket now correctly returns the socket.
  Patch by Farhan Ahmad, test by Marcin Bachry.

- Issue #2116: Weak references and weak dictionaries now support copy()ing and
  deepcopy()ing.

- Issue #1655: Make imaplib IPv6-capable. Patch by Derek Morr.

- Issue #5918: Fix a crash in the parser module.

- Issue #1664: Make nntplib IPv6-capable. Patch by Derek Morr.

- Issue #5006: Better handling of unicode byte-order marks (BOM) in the io
  library. This means, for example, that opening an UTF-16 text file in
  append mode doesn't add a BOM at the end of the file if the file isn't
  empty.

- Issue #4050: inspect.findsource/getsource now raise an IOError if the 'source'
  file is a binary.  Patch by Brodie Rao, tests by Daniel Diniz.  This fix
  corrects a pydoc regression.

- Issue #5955: aifc's close method did not close the file it wrapped,
  now it does.  This also means getfp method now returns the real fp.

Installation
------------

- Issue #6047: fullinstall has been removed because Python 3's executable will
  now be known as python3.

- Lib/smtpd.py is no longer installed as a script.

Extension Modules
-----------------

- Issue #3061: Use wcsftime for time.strftime where available.

- Issue #4873: Fix resource leaks in error cases of pwd and grp.

- Issue #6093: Fix off-by-one error in locale.strxfrm.

- The _functools and _locale modules are now built into the libpython shared
  library instead of as extension modules.

Build
-----

- Issue #3585: Add pkg-config support. It creates a python-2.7.pc file
  and a python3.pc symlink in the $(LIBDIR)/pkgconfig directory. Patch by
  Clinton Roy.

Tests
-----

- Issue #5442: Tests for importlib were not properly skipping case-sensitivity
  tests on darwin even when the OS was installed on a case-sensitive
  filesystem. Also fixed tests that should not be run when
  sys.dont_write_bytecode is true.


What's New in Python 3.1 beta 1?
================================

*Release date: 2009-05-06*

Core and Builtins
-----------------

- Issue #5914: Add new C API function PyOS_string_to_double, and
  deprecate PyOS_ascii_strtod and PyOS_ascii_atof.

- Issue #3382: float.__format__, complex.__format__, and %-formatting
  no longer map 'F' to 'f'. Because of issue #5859 (below), this only
  affects nan -> NAN and inf -> INF.

- Issue #5799: ntpath (ie, os.path on Windows) fully supports UNC pathnames
  in all operations, including splitdrive, split, etc.  splitunc() now issues
  a PendingDeprecation warning.

- Issue #5920: For float.__format__, change the behavior with the
  empty presentation type (that is, not one of 'e', 'f', 'g', or 'n')
  to be like 'g' but with at least one decimal point and with a
  default precision of 12. Previously, the behavior the same but with
  a default precision of 6.  This more closely matches str(), and
  reduces surprises when adding alignment flags to the empty
  presentation type. This also affects the new complex.__format__ in
  the same way.

- Implement PEP 383, Non-decodable Bytes in System Character Interfaces.

- Issue #5890: in subclasses of 'property' the __doc__ attribute was
  shadowed by classtype's, even if it was None.  property now
  inserts the __doc__ into the subclass instance __dict__.

- Issue #4426: The UTF-7 decoder was too strict and didn't accept some legal
  sequences. Patch by Nick Barnes and Victor Stinner.

- Issue #3672: Reject surrogates in utf-8 codec; add surrogatepass error handler.

- Issue #5883: In the io module, the BufferedIOBase and TextIOBase ABCs have
  received a new method, detach().  detach() disconnects the underlying stream
  from the buffer or text IO and returns it.

- Issue #5859: Remove switch from '%f' to '%g'-style formatting for
  floats with absolute value over 1e50.  Also remove length
  restrictions for float formatting: '%.67f' % 12.34 and '%.120e' %
  12.34 no longer raise an exception.

- Issue #1588: Add complex.__format__. For example,
  format(complex(1, 2./3), '.5') now produces a sensible result.

- Issue #5864: Fix empty format code formatting for floats so that it
  never gives more than the requested number of significant digits.

- Issue #5793: Rationalize isdigit / isalpha / tolower, etc. Includes
  new Py_ISDIGIT / Py_ISALPHA / Py_TOLOWER, etc. in pctypes.h.

- Issue #5835: Deprecate PyOS_ascii_formatd.

- Issue #4971: Fix titlecase for characters that are their own
  titlecase, but not their own uppercase.

- Issue #5283: Setting __class__ in __del__ caused a segfault.

- Issue #5816: complex(repr(z)) now recovers z exactly, even when
  z involves nans, infs or negative zeros.

- Issue #3166: Make int -> float conversions correctly rounded.

- Issue #1869 (and many duplicates): make round(x, n) correctly
  rounded for a float x, by using the decimal <-> binary conversions
  from Python/dtoa.c.  As a consequence, (e.g.) round(x, 2) now
  consistently agrees with format(x, '.2f').

- Issue #5787: object.__getattribute__(some_type, "__bases__") segfaulted on
  some builtin types.

- Issue #5772: format(1e100, '<') produces '1e+100', not '1.0e+100'.

- Issue #5515: str.format() type 'n' combined with commas and leading
  zeros no longer gives odd results with ints and floats.

- Implement PEP 378, Format Specifier for Thousands Separator, for
  floats.

- The str function switches to exponential notation at
  1e11, not 1e12.  This avoids printing 13 significant digits in
  situations where only 12 of them are correct.  Example problem
  value: str(1e11 + 0.5).  (This minor issue has existed in 2.x for a
  long time.)

- Issue #1580: On most platforms, use a 'short' float repr: for a
  finite float x, repr(x) now outputs a string based on the shortest
  sequence of decimal digits that rounds to x.  Previous behaviour was
  to output 17 significant digits and then strip trailing zeros.
  Another minor difference is that the new repr switches to
  exponential notation at 1e16 instead of the previous 1e17; this
  avoids misleading output in some cases.

  There's a new sys attribute sys.float_repr_style, which takes
  the value 'short' to indicate that we're using short float repr,
  and 'legacy' if the short float repr isn't available for one
  reason or another.

  The float repr change involves incorporating David Gay's 'perfect
  rounding' code into the Python core (it's in Python/dtoa.c).  As a
  secondary consequence, all string-to-float and float-to-string
  conversions (including all float formatting operations) will be
  correctly rounded on these platforms.

  See issue #1580 discussions for details of platforms for which
  this change does not apply.

- Issue #5759: float() didn't call __float__ on str subclasses.

- The string.maketrans() function is deprecated; there is a new static method
  maketrans() on the bytes and bytearray classes.  This removes confusion about
  the types string.maketrans() is supposed to work with, and mirrors the
  methods available on the str class.

- Issue #2170: refactored xml.dom.minidom.normalize, increasing both
  its clarity and its speed.

- Issue #1113244: Py_XINCREF, Py_DECREF, Py_XDECREF: Add ``do { ... } while (0)``
  to avoid compiler warnings.

- Issue #3739: The unicode-internal encoder now reports the number of characters
  consumed like any other encoder (instead of the number of bytes).

Installation
------------

- Issue #5756: Install idle and pydoc with a 3 suffix.

Library
-------

- Issue #8203: Fix IDLE Credits dialog: view_file() uses its encoding argument.

- Issue #5311: bdist_msi can now build packages that do not depend on a
  specific Python version.

- Issue #5150: IDLE's format menu now has an option to strip trailing
  whitespace.

- Issue #5940: distutils.command.build_clib.check_library_list was not doing
  the right type checkings anymore.

- Issue #4875: On win32, ctypes.util.find_library does no longer
  return directories.

- Issue #5142: Add the ability to skip modules while stepping to pdb.

- Issue #1309567: Fix linecache behavior of stripping subdirectories when
  looking for files given by a relative filename.

- Issue #5923: Update the ``turtle`` module to version 1.1, add two new
  turtle demos in Demo/turtle.

- Issue #5692: In ``zipfile.Zipfile``, fix wrong path calculation when
  extracting a file to the root directory.

- Issue #5913: os.listdir() should fail for empty path on windows.

- Issue #5084: unpickling now interns the attribute names of pickled objects,
  saving memory and avoiding growth in size of subsequent pickles. Proposal
  and original patch by Jake McGuire.

- The json module now works exclusively with str and not bytes.

- Issue #3959: The ipaddr module has been added to the standard library.
  Contributed by Google.

- Issue #3002: ``shutil.copyfile()`` and ``shutil.copytree()`` now raise an
  error when a named pipe is encountered, rather than blocking infinitely.

- Issue #5857: tokenize.tokenize() now returns named tuples.

- Issue #4305: ctypes should now build again on mipsel-linux-gnu

- Issue #1734234: Massively speedup ``unicodedata.normalize()`` when the
  string is already in normalized form, by performing a quick check beforehand.
  Original patch by Rauli Ruohonen.

- Issue #5853: calling a function of the mimetypes module from several threads
  at once could hit the recursion limit if the mimetypes database hadn't been
  initialized before.

- Issue #5854: Updated __all__ to include some missing names and remove some
  names which should not be exported.

- Issue #3102:  All global symbols that the _ctypes extension defines
  are now prefixed with 'Py' or '_ctypes'.

- Issue #5041: ctypes does now allow pickling wide character.

- Issue #5812: For the two-argument form of the Fraction constructor,
  Fraction(m, n), m and n are permitted to be arbitrary Rational
  instances.

- Issue #5812: Fraction('1e6') is valid: more generally, any string
  that's valid for float() is now valid for Fraction(), with the
  exception of strings representing NaNs and infinities.

- Issue #5734: BufferedRWPair was poorly tested and had several glaring
  bugs. Patch by Brian Quinlan.

- Issue #1161031: fix readwrite select flag handling: POLLPRI now
  results in a handle_expt_event call, not handle_read_event, and POLLERR
  and POLLNVAL now call handle_close, not handle_expt_event.  Also,
  dispatcher now has an 'ignore_log_types' attribute for suppressing
  log messages, which is set to 'warning' by default.

- Issue #2703: SimpleXMLRPCDispatcher.__init__: Provide default values for
  new arguments introduced in 2.5.

- Issue #5828 (Invalid behavior of unicode.lower): Fixed bogus logic in
  makeunicodedata.py and regenerated the Unicode database (This fixes
  u'\u1d79'.lower() == '\x00').

Extension Modules
-----------------

- Issue #5881: Remove old undocumented compatibility interfaces in hashlib and
  pwd.

- Issue #5463: In struct module, remove deprecated float coercion
  for integer type codes: struct.pack('L', 0.3) should now raise
  an error.  The _PY_STRUCT_FLOAT_COERCE constant has been removed.
  The version number has been bumped to 0.3.

- Issue #5359: Readd the Berkeley DB detection code to allow _dbm be built
  using Berkeley DB.

Tests
-----

- Issue #5354: New test support function import_fresh_module() makes
  it easy to import both normal and optimised versions of modules.
  test_heapq and test_warnings have been adjusted to use it, tests for
  other modules with both C and Python implementations in the stdlib
  can be adjusted to use it over time.

- Issue #5837: Certain sequences of calls to set() and unset() for
  support.EnvironmentVarGuard objects restored the environment variables
  incorrectly on __exit__.

C-API
-----

- Issue #5630: A replacement PyCObject API, PyCapsule, has been added.


What's New in Python 3.1 alpha 2?
=================================

*Release date: 2009-4-4*

Core and Builtins
-----------------

- Implement PEP 378, Format Specifier for Thousands Separator, for
  integers.

- Issue #5666: Py_BuildValue's 'c' code should create byte strings.

- Issue #5499: The 'c' code for argument parsing functions now only accepts a
  byte, and the 'C' code only accepts a unicode character.

- Fix a problem in PyErr_NormalizeException that leads to "undetected errors"
  when hitting the recursion limit under certain circumstances.

- Issue #1665206: Remove the last eager import in _warnings.c and make it lazy.

- Fix a segfault when running test_exceptions with coverage, caused by
  insufficient checks in accessors of Exception.__context__.

- Issue #5604: non-ASCII characters in module name passed to
  imp.find_module() were converted to UTF-8 while the path is
  converted to the default filesystem encoding, causing nonsense.

- Issue #5126: str.isprintable() returned False for space characters.

- Issue #4865: On MacOSX /Library/Python/2.7/site-packages is added to
  the end sys.path, for compatibility with the system install of Python.

- Issue #4688: Add a heuristic so that tuples and dicts containing only
  untrackable objects are not tracked by the garbage collector. This can
  reduce the size of collections and therefore the garbage collection overhead
  on long-running programs, depending on their particular use of datatypes.

- Issue #5512: Rewrite PyLong long division algorithm (x_divrem) to
  improve its performance.  Long divisions and remainder operations
  are now between 50% and 150% faster.

- Issue #4258: Make it possible to use base 2**30 instead of base
  2**15 for the internal representation of integers, for performance
  reasons.  Base 2**30 is enabled by default on 64-bit machines.  Add
  --enable-big-digits option to configure, which overrides the
  default.  Add sys.int_info structseq to provide information about
  the internal format.

- Issue #4474: PyUnicode_FromWideChar now converts characters outside
  the BMP to surrogate pairs, on systems with sizeof(wchar_t) == 4
  and sizeof(Py_UNICODE) == 2.

- Issue #5237: Allow auto-numbered fields in str.format(). For
  example: '{} {}'.format(1, 2) == '1 2'.

- Issue #5392: when a very low recursion limit was set, the interpreter would
  abort with a fatal error after the recursion limit was hit twice.

- Issue #3845: In PyRun_SimpleFileExFlags avoid invalid memory access with
  short file names.

Library
-------

- Issue #2625: added missing items() call to the for loop in
  mailbox.MH.get_message().

- Issue #5640: Fix _multibytecodec so that CJK codecs don't repeat
  error substitutions from non-strict codec error callbacks in
  incrementalencoder and StreamWriter.

- Issue #5656: Fix the coverage reporting when running the test suite with
  the -T argument.

- Issue #5647: MutableSet.__iand__() no longer mutates self during iteration.

- Issue #5624: Fix the _winreg module name still used in several modules.

- Issue #5628: Fix io.TextIOWrapper.read() with a unreadable buffer.

- Issue #5619: Multiprocessing children disobey the debug flag and causes
  popups on windows buildbots. Patch applied to work around this issue.

- Issue #5400: Added patch for multiprocessing on netbsd compilation/support

- Issue #5387: Fixed mmap.move crash by integer overflow.

- Issue #5261: Patch multiprocessing's semaphore.c to support context
  manager use: "with multiprocessing.Lock()" works now.

- Issue #5236: Change time.strptime() to only take strings. Didn't work with
  bytes already but the failure was non-obvious.

- Issue #5177: Multiprocessing's SocketListener class now uses
  socket.SO_REUSEADDR on all connections so that the user no longer needs
  to wait 120 seconds for the socket to expire.

- Issue #5595: Fix UnboundedLocalError in ntpath.ismount().

- Issue #1174606: Calling read() without arguments of an unbounded file
  (typically /dev/zero under Unix) could crash the interpreter.

- The max_buffer_size arguments of io.BufferedWriter, io.BufferedRWPair, and
  io.BufferedRandom have been deprecated for removal in Python 3.2.

- Issue #5068: Fixed the tarfile._BZ2Proxy.read() method that would loop
  forever on incomplete input. That caused tarfile.open() to hang when used
  with mode 'r' or 'r:bz2' and a fileobj argument that contained no data or
  partial bzip2 compressed data.

- Issue #2110: Add support for thousands separator and 'n' type
  specifier to Decimal.__format__

- Fix Decimal.__format__ bug that swapped the meanings of the '<' and
  '>' alignment characters.

- The error detection code in FileIO.close() could fail to reflect the `errno`
  value, and report it as -1 instead.

- Issue #5016: FileIO.seekable() could return False if the file position
  was negative when truncated to a C int. Patch by Victor Stinner.

Extension Modules
-----------------

- Issue #5391: mmap now deals exclusively with bytes.

- Issue #5463: In struct module, remove deprecated overflow wrapping
  when packing an integer: struct.pack('=L', -1) now raises
  struct.error instead of returning b'\xff\xff\xff\xff'.  The
  _PY_STRUCT_RANGE_CHECKING and _PY_STRUCT_OVERFLOW_MASKING constants
  have been removed from the struct module.


What's New in Python 3.1 alpha 1
================================

*Release date: 2009-03-07*

Core and Builtins
-----------------

- The io module has been reimplemented in C for speed.

- Give dict views an informative __repr__.

- Issue #5247: Improve error message when unknown format codes are
  used when using str.format() with str, int, and float arguments.

- Issue #5249: time.strftime returned malformed string when format string
  contained non ascii character on windows.

- Issue #4626: compile(), exec(), and eval() ignore the coding cookie if the
  source has already been decoded into str.

- Issue #5186: Reduce hash collisions for objects with no __hash__ method by
  rotating the object pointer by 4 bits to the right.

- Issue #4575: Fix Py_IS_INFINITY macro to work correctly on x87 FPUs:
  it now forces its argument to double before testing for infinity.

- Issue #5137: Make len() correctly raise a TypeError when a __len__ method
  returns a non-number type.

- Issue #5182: Removed memoryview.__str__.

- Issue #1717: Removed builtin cmp() function, dropped tp_compare
  slot, the C API functions PyObject_Compare and PyUnicode_Compare and
  the type definition cmpfunc.  The tp_compare slot has been renamed
  to tp_reserved, and is reserved for future usage.

- Issue #1242657: the __len__() and __length_hint__() calls in several tools
  were suppressing all exceptions.  These include list() and bytearray().

- Issue #4707: round(x, n) now returns an integer if x is an integer.
  Previously it returned a float.

- Issue #4753: By enabling a configure option named '--with-computed-gotos'
  on compilers that support it (notably: gcc, SunPro, icc), the bytecode
  evaluation loop is compiled with a new dispatch mechanism which gives
  speedups of up to 20%, depending on the system, on various benchmarks.

- Issue #4874: Most builtin decoders now reject unicode input.

- Issue #4842: Don't allow trailing 'L' when constructing an integer
  from a string.

- Issue #4991: os.fdopen now raises an OSError for invalid file descriptors.

- Issue #4838: When a module is deallocated, free the memory backing the
  optional module state data.

- Issue #4910: Rename nb_long slot to nb_reserved, and change its
  type to ``(void *)``.

- Issue #4935: The overflow checking code in the expandtabs() method common
  to str, bytes and bytearray could be optimized away by the compiler, letting
  the interpreter segfault instead of raising an error.

- Issue #3720: Fix a crash when an iterator modifies its class and removes its
  __next__ method.

- Issue #4910: Builtin int() function and PyNumber_Long/PyNumber_Int API
  function no longer attempt to call the __long__ slot to convert an object
  to an integer.  Only the __int__ and __trunc__ slots are examined.

- Issue #4893: Use NT threading on CE.

- Issue #4915: Port sysmodule to Windows CE.

- Issue #4868: utf-8, utf-16 and latin1 decoding are now 2x to 4x faster. The
  common cases are optimized thanks to a dedicated fast path and a moderate
  amount of loop unrolling.

- Issue #4074: Change the criteria for doing a full garbage collection (i.e.
  collecting the oldest generation) so that allocating lots of objects without
  destroying them does not show quadratic performance. Based on a proposal by
  Martin von Löwis at
  http://mail.python.org/pipermail/python-dev/2008-June/080579.html.

- Issue #4604: Some objects of the I/O library could still be used after
  having been closed (for instance, a read() call could return some
  previously buffered data). Patch by Dmitry Vasiliev.

- Issue #4705: Fix the -u ("unbuffered binary stdout and stderr") command-line
  flag to work properly. Furthermore, when specifying -u, the text stdout
  and stderr streams have line-by-line buffering enabled (the default being
  to buffer arbitrary chunks of data).

- The internal table, _PyLong_DigitValue, is now an array of unsigned chars
  instead of ints (reducing its size from 4 to 8 times thereby reducing
  Python's overall memory).

- Issue #1180193: When importing a module from a .pyc (or .pyo) file with
  an existing .py counterpart, override the co_filename attributes of all
  code objects if the original filename is obsolete (which can happen if the
  file has been renamed, moved, or if it is accessed through different paths).
  Patch by Ziga Seilnacht and Jean-Paul Calderone.

- Issue #4580: Fix slicing of memoryviews when the item size is greater than
  one byte. Also fixes the meaning of len() so that it returns the number of
  items, rather than the size in bytes.

- Issue #4075: Use OutputDebugStringW in Py_FatalError.

- Issue #4747: When the terminal does not use utf-8, executing a script with
  non-ascii characters in its name could fail with a "SyntaxError: None" error.

- Issue #4797: IOError.filename was not set when ``_fileio.FileIO`` failed
  to open file with a bytes filename on Windows.

- Issue #3680: Reference cycles created through a dict, set or deque iterator
  did not get collected.

- Issue #4701: PyObject_Hash now implicitly calls PyType_Ready on types
  where the tp_hash and tp_dict slots are both NULL.

- Issue #4759: None is now allowed as the first argument of
  bytearray.translate().  It was always allowed for bytes.translate().

- Added test case to ensure attempts to read from a file opened for writing
  fail.

- Issue #3106: Speedup some comparisons (str/str and int/int).

- Issue #2183: Simplify and optimize bytecode for list, dict and set
  comprehensions. Original patch for list comprehensions by Neal Norwitz.

- Issue #2467: gc.DEBUG_STATS reported invalid elapsed times. Also, always
  print elapsed times, not only when some objects are uncollectable /
  unreachable. Original patch by Neil Schemenauer.

- Issue #3439: Add a bit_length method to int.

- Issue #2173: When getting device encoding, check that return value of
  nl_langinfo is not the empty string.  This was causing silent build
  failures on OS X.

- Issue #4597: Fixed several opcodes that weren't always propagating
  exceptions.

- Issue #4589: Fixed exception handling when the __exit__ function of a
  context manager returns a value that cannot be converted to a bool.

- Issue #4445: Replace "sizeof(PyBytesObject)" with
  "offsetof(PyBytesObject, ob_sval) + 1" when allocating memory for
  bytes instances.  On a typical machine this saves 3 bytes of memory
  (on average) per allocation of a bytes instance.

- Issue #4533: File read operation was dreadfully slow due to a slowly
  growing read buffer. Fixed by using the same growth rate algorithm as
  Python 2.x.

- Issue #4509: Various issues surrounding resize of bytearray objects to
  which there are buffer exports (e.g. memoryview instances).

- Issue #4233: Changed semantic of ``_fileio.FileIO``'s ``close()``
  method on file objects with closefd=False. The file descriptor is still
  kept open but the file object behaves like a closed file. The ``FileIO``
  object also got a new readonly attribute ``closefd``.

- Issue #4569: Interpreter crash when mutating a memoryview with an item size
  larger than 1.

- Issue #4748: Lambda generators no longer return a value.

- The re.sub(), re.subn() and re.split() functions now accept a flags parameter.

- Issue #5108: Handle %s like %S, %R and %A in PyUnicode_FromFormatV(): Call
  PyUnicode_DecodeUTF8() once, remember the result and output it in a second
  step. This avoids problems with counting UTF-8 bytes that ignores the effect
  of using the replace error handler in PyUnicode_DecodeUTF8().

Library
-------

- Issue #7071: byte-compilation in Distutils is now done with respect to
  sys.dont_write_bytecode.

- Issue #7066: archive_util.make_archive now restores the cwd if an error is
  raised. Initial patch by Ezio Melotti.

- Issue #6516: Added owner/group support when creating tar archives in
  Distutils.

- Issue #6954: Fixed crash when using DISTUTILS_DEBUG flag in Distutils.

- Issue #6163: Fixed HP-UX runtime library dir options in
  distutils.unixcompiler. Initial patch by Sridhar Ratnakumar and
  Michael Haubenwallner.

- Issue #6693: New functions in site.py to get user/global site packages paths.

- Issue #6511: ZipFile now raises BadZipfile (instead of an IOError) when
  opening an empty or very small file.

- Issue #6545: Removed assert statements in distutils.Extension, so the
  behavior is similar when used with -O.

- unittest has been split up into a package.  All old names should still work.

- Issue #6466: now distutils.cygwinccompiler and distutils.emxccompiler
  uses the same refactored function to get gcc/ld/dllwrap versions numbers.
  It's `distutils.util.get_compiler_versions`. Added deprecation warnings
  for the obsolete get_versions() functions.

- Issue #6433: fixed issues with multiprocessing.pool.map hanging on empty list

- Issue #6314: logging: Extra checks on the "level" argument in more places.

- Issue #2622: Fixed an ImportError when importing email.message from a
  standalone application built with py2exe or py2app.

- Issue #6455: Fixed test_build_ext under win32.

- Issue #6377: Enabled the compiler option, and deprecate its usage as an
  attribute.

- Issue #6413: Fixed the log level in distutils.dist for announce.

- Issue #6403: Fixed package path usage in build_ext.

- Issues #5155, 5313, 5331: multiprocessing.Process._bootstrap was
  unconditionally calling "os.close(sys.stdin.fileno())" resulting in file
  descriptor errors

- Issue #6365: Distutils build_ext inplace mode was copying the compiled
  extension in a subdirectory if the extension name had dots.

- Issue #6164: Added an AIX specific linker argument in Distutils
  unixcompiler. Original patch by Sridhar Ratnakumar.

- Issue #6286: Now Distutils upload command is based on urllib2 instead of
  httplib, allowing the usage of http_proxy.

- Issue #6287: Added the license field in Distutils documentation.

- Issue #6263: Fixed syntax error in distutils.cygwincompiler.

- Issue #5201: distutils.sysconfig.parse_makefile() now understands `$$`
  in Makefiles. This prevents compile errors when using syntax like:
  `LDFLAGS='-rpath=\$$LIB:/some/other/path'`. Patch by Floris Bruynooghe.

- Issue #6131: test_modulefinder leaked when run after test_distutils.
  Patch by Hirokazu Yamamoto.

- Issue #6048: Now Distutils uses the tarfile module in archive_util.

- Issue #6062: In distutils, fixed the package option of build_ext. Feedback
  and tests on pywin32 by Tim Golden.

- Issue #6053: Fixed distutils tests on win32. patch by Hirokazu Yamamoto.

- Issue #6046: Fixed the library extension when distutils build_ext is used
  inplace. Initial patch by Roumen Petrov.

- Issue #6041: Now distutils `sdist` and `register` commands use `check` as a
  subcommand.

- Issue #6022: a test file was created in the current working directory by
  test_get_outputs in Distutils.

- Issue #5977: distutils build_ext.get_outputs was not taking into account the
  inplace option. Initial patch by kxroberto.

- Issue #5984: distutils.command.build_ext.check_extensions_list checks were broken
  for old-style extensions.

- Issue #5976: Fixed Distutils test_check_environ.

- Issue #5941: Distutils build_clib command was not working anymore because
  of an incomplete costumization of the archiver command. Added ARFLAGS in the
  Makefile besides AR and make Distutils use it. Original patch by David
  Cournapeau.

- Issue #2245: aifc now skips chunk types it doesn't recognize, per spec.

- Issue #5874: distutils.tests.test_config_cmd is not locale-sensitive
  anymore.

- Issue #5810: Fixed Distutils test_build_scripts so it uses
  sysconfig.get_config_vars.

- Issue #4951: Fixed failure in test_httpservers.

- Issue #5795: Fixed test_distutils failure on Debian ppc.

- Issue #5607: fixed Distutils test_get_platform for Mac OS X fat binaries.

- Issue #5741: don't disallow "%%" (which is an escape for "%") when setting
  a value in SafeConfigParser.

- Issue #5732: added a new command in Distutils: check.

- Issue #5731: Distutils bdist_wininst no longer worked on non-Windows
  platforms. Initial patch by Paul Moore.

- Issue #5095: Added bdist_msi to the list of bdist supported formats.
  Initial fix by Steven Bethard.

- Issue #1491431: Fixed distutils.filelist.glob_to_re for edge cases.
  Initial fix by Wayne Davison.

- Issue #5694: removed spurious test output in Distutils (test_clean).

- Issue #1326077: fix the formatting of SyntaxErrors by the traceback module.

- Issue #1665206 (partially): Move imports in cgitb to the top of the module
  instead of performing them in functions. Helps prevent import deadlocking in
  threads.

- Issue #2522: locale.format now checks its first argument to ensure it has
  been passed only one pattern, avoiding mysterious errors where it appeared
  that it was failing to do localization.

- Issue #5583: Added optional Extensions in Distutils. Initial patch by Georg
  Brandl.

- Issue #1222: locale.format() bug when the thousands separator is a space
  character.

- Issue #5472: Fixed distutils.test_util tear down. Original patch by
  Tim Golden.

- collections.deque() objects now have a read-only attribute called maxlen.

- Issue #2638: Show a window constructed with tkSimpleDialog.Dialog only after
  it is has been populated and properly configured in order to prevent
  window flashing.

- Issue #4792: Prevent a segfault in _tkinter by using the
  guaranteed to be safe interp argument given to the PythonCmd in place of
  the Tcl interpreter taken from a PythonCmd_ClientData.

- Issue #5193: Guarantee that tkinter.Text.search returns a string.

- Issue #5394: removed > 2.3 syntax from distutils.msvc9compiler.
  Original patch by Akira Kitada.

- Issue #5334: array.fromfile() failed to insert values when EOFError was raised.

- Issue #5385: Fixed mmap crash after resize failure on windows.

- Issue #5179: Fixed subprocess handle leak on failure on windows.

- PEP 372:  Added collections.OrderedDict().

- The _asdict() for method for namedtuples now returns an OrderedDict().

- configparser now defaults to using an ordered dictionary.

- Issue #5401: Fixed a performance problem in mimetypes when ``from mimetypes
  import guess_extension`` was used.

- Issue #1733986: Fixed mmap crash in accessing elements of second map object
  with same tagname but larger size than first map. (Windows)

- Issue #5386: mmap.write_byte didn't check map size, so it could cause buffer
  overrun.

- Issue #1533164: Installed but not listed ``*.pyo`` was breaking Distutils
  bdist_rpm command.

- Issue #5378: added --quiet option to Distutils bdist_rpm command.

- Issue #5052: make Distutils compatible with 2.3 again.

- Issue #5316: Fixed buildbot failures introduced by multiple inheritance
  in Distutils tests.

- Issue #5287: Add exception handling around findCaller() call to help out
  IronPython.

- Issue #5282: Fixed mmap resize on 32bit windows and unix. When offset > 0,
  The file was resized to wrong size.

- Issue #5292: Fixed mmap crash on its boundary access m[len(m)].

- Issue #2279: distutils.sdist.add_defaults now add files
  from the package_data and the data_files metadata.

- Issue #5257: refactored all tests in distutils, so they use
  support.TempdirManager, to avoid writing in the tests directory.

- Issue #4524: distutils build_script command failed with --with-suffix=3.
  Initial patch by Amaury Forgeot d'Arc.

- Issue #2461: added tests for distutils.util

- Issue #4998: The memory saving effect of __slots__ had been lost on Fractions
  which inherited from numbers.py which did not have __slots__ defined.  The
  numbers hierarchy now has its own __slots__ declarations.

- Issue #4631: Fix urlopen() result when an HTTP response uses chunked
  encoding.

- Issue #5203: Fixed ctypes segfaults when passing a unicode string to a
  function without argtypes (only occurs if HAVE_USABLE_WCHAR_T is false).

- Issue #3386: distutils.sysconfig.get_python_lib prefix argument was ignored
  under NT and OS2. Patch by Philip Jenvey.

- Issue #5128: Make compileall properly inspect bytecode to determine if needs
  to be recreated. This avoids a timing hole thanks to the old reliance on the
  ctime of the files involved.

- Issue #5122: Synchronize tk load failure check to prevent a potential
  deadlock.

- Issue #1818: collections.namedtuple() now supports a keyword argument
  'rename' which lets invalid fieldnames be automatically converted to
  positional names in the form, _1, _2, ...

- Issue #4890: Handle empty text search pattern in Tkinter.Text.search.

- Issue #4512 (part 2): Promote ``ZipImporter._get_filename()`` to be a
  public documented method ``ZipImporter.get_filename()``.

- Issue #4195: The ``runpy`` module (and the ``-m`` switch) now support
  the execution of packages by looking for and executing a ``__main__``
  submodule when a package name is supplied. Initial patch by Andi
  Vajda.

- Issue #1731706: Call Tcl_ConditionFinalize for Tcl_Conditions that will
  not be used again (this requires Tcl/Tk 8.3.1), also fix a memory leak in
  Tkapp_Call when calling from a thread different than the one that created
  the Tcl interpreter. Patch by Robert Hancock.

- Issue #4285: Change sys.version_info to be a named tuple. Patch by
  Ross Light.

- Issue #1520877: Now distutils.sysconfig reads $AR from the
  environment/Makefile. Patch by Douglas Greiman.

- Issue #1276768: The verbose option was not used in the code of
  distutils.file_util and distutils.dir_util.

- Issue #5132: Fixed trouble building extensions under Solaris with
  --enabled-shared activated. Initial patch by Dave Peterson.

- Issue #1581476: Always use the Tcl global namespace when calling into Tcl.

- The shelve module now defaults to pickle protocol 3.

- Fix a bug in the trace module where a bytes object from co_lnotab had its
  items being passed through ord().

- Issue #2047: shutil.move() could believe that its destination path was
  inside its source path if it began with the same letters (e.g. "src" vs.
  "src.new").

- Added the ttk module. See issue #2983: Ttk support for Tkinter.

- Removed isSequenceType(), isMappingType, and isNumberType() from the
  operator module; use the abstract base classes instead.  Also removed
  the repeat() function; use mul() instead.

- Issue #5021:  doctest.testfile() did not create __name__ and
  collections.namedtuple() relied on __name__ being defined.

- Backport importlib from Python 3.1. Only the import_module() function has
  been backported to help facilitate transitions from 2.7 to 3.1.

- Issue #1885: distutils. When running sdist with --formats=tar,gztar
  the tar file was overriden by the gztar one.

- Issue #4863: distutils.mwerkscompiler has been removed.

- Added a new itertools functions:  combinations_with_replacement()
  and compress().

- Issue #5032:  added a step argument to itertools.count() and
  allowed non-integer arguments.

- Fix and properly document the multiprocessing module's logging
  support, expose the internal levels and provide proper usage
  examples.

- Issue #1672332: fix unpickling of subnormal floats, which was
  producing a ValueError on some platforms.

- Issue #3881: Help Tcl to load even when started through the
  unreadable local symlink to "Program Files" on Vista.

- Issue #4710: Extract directories properly in the zipfile module;
  allow adding directories to a zipfile.

- Issue #3807: _multiprocessing build fails when configure is passed
  --without-threads argument. When this occurs, _multiprocessing will
  be disabled, and not compiled.

- Issue #5008: When a file is opened in append mode with the new IO library,
  do an explicit seek to the end of file (so that e.g. tell() returns the
  file size rather than 0). This is consistent with the behaviour of the
  traditional 2.x file object.

- Issue #5013: Fixed a bug in FileHandler which occurred when the delay
  parameter was set.

- Issue #4842: Always append a trailing 'L' when pickling longs using
  pickle protocol 0.  When reading, the 'L' is optional.

- Add the importlib package.

- Issue #4301: Patch the logging module to add processName support, remove
  _check_logger_class from multiprocessing.

- Issue #3325: Remove python2.x try: except: imports for old cPickle from
  multiprocessing.

- Issue #4959: inspect.formatargspec now works for keyword only arguments
  without defaults.

- Issue #3321: ``_multiprocessing.Connection()`` doesn't check handle; added checks
  for Unix machines for negative handles and large int handles. Without this check
  it is possible to segfault the interpreter.

- Issue #4449: AssertionError in mp_benchmarks.py, caused by an underlying issue
  in sharedctypes.py.

- Issue #1225107: inspect.isclass() returned True for instances with a custom
  __getattr__.

- Issue #3826 and #4791: The socket module now closes the underlying socket
  appropriately when it is being used via socket.makefile() objects
  rather than delaying the close by waiting for garbage collection to do it.

- Issue #1696199:  Add collections.Counter() for rapid and convenient
  counting.

- Issue #3860: GzipFile and BZ2File now support the context manager protocol.

- Issue #4867: Fixed a crash in ctypes when passing a string to a
  function without defining argtypes.

- Issue #4272: Add an optional argument to the GzipFile constructor to override
  the timestamp in the gzip stream. The default value remains the current time.
  The information can be used by e.g. gunzip when decompressing. Patch by
  Jacques Frechet.

- Restore Python 2.3 compatibility for decimal.py.

- Issue #3638: Remove functions from _tkinter module level that depend on
  TkappObject to work with multiple threads.

- Issue #4718: Adapt the wsgiref package so that it actually works with
  Python 3.x, in accordance with the `official amendments of the spec
  <http://www.wsgi.org/wsgi/Amendments_1.0>`_.

- Issue #4796: Added Decimal.from_float() and Context.create_decimal_from_float()
  to the decimal module.

- Fractions.from_float() no longer loses precision for integers too big to
  cast as floats.

- Issue #4812: add missing underscore prefix to some internal-use-only
  constants in the decimal module.  (Dec_0 becomes _Dec_0, etc.)

- Issue #4790: The nsmallest() and nlargest() functions in the heapq module
  did unnecessary work in the common case where no key function was specified.

- Issue #4795: inspect.isgeneratorfunction() returns False instead of None when
  the function is not a generator.

- Issue #4702: Throwing a DistutilsPlatformError instead of IOError in case
  no MSVC compiler is found under Windows. Original patch by Philip Jenvey.

- Issue #4646: distutils was choking on empty options arg in the setup
  function. Original patch by Thomas Heller.

- Issue #3767: Convert Tk object to string in tkColorChooser.

- Issue #3248: Allow placing ScrolledText in a PanedWindow.

- Issue #4444: Allow assertRaises() to be used as a context handler, so that
  the code under test can be written inline if more practical.

- Issue #4739: Add pydoc help topics for symbols, so that e.g. help('@')
  works as expected in the interactive environment.

- Issue #4756: zipfile.is_zipfile() now supports file-like objects. Patch by
  Gabriel Genellina.

- Issue #4574: reading an UTF16-encoded text file crashes if \r on 64-char
  boundary.

- Issue #4223: inspect.getsource() will now correctly display source code
  for packages loaded via zipimport (or any other conformant PEP 302
  loader). Original patch by Alexander Belopolsky.

- Issue #4201: pdb can now access and display source code loaded via
  zipimport (or any other conformant PEP 302 loader). Original patch by
  Alexander Belopolsky.

- Issue #4197: doctests in modules loaded via zipimport (or any other PEP
  302 conformant loader) will now work correctly in most cases (they
  are still subject to the constraints that exist for all code running
  from inside a module loaded via a PEP 302 loader and attempting to
  perform IO operations based on __file__). Original patch by
  Alexander Belopolsky.

- Issues #4082 and #4512: Add runpy support to zipimport in a manner that
  allows backporting to maintenance branches. Original patch by
  Alexander Belopolsky.

- Issue #4163: textwrap module: allow word splitting on a hyphen preceded by
  a non-ASCII letter.

- Issue #4616: TarFile.utime(): Restore directory times on Windows.

- Issue #4021: tokenize.detect_encoding() now raises a SyntaxError when the
  codec cannot be found.  This is for compatibility with the builtin behavior.

- Issue #4084: Fix max, min, max_mag and min_mag Decimal methods to
  give correct results in the case where one argument is a quiet NaN
  and the other is a finite number that requires rounding.

- Issue #4483: _dbm module now builds on systems with gdbm & gdbm_compat
  libs.

- Added the subprocess.check_call_output() convenience function to get output
  from a subprocess on success or raise an exception on error.

- Issue #1055234: cgi.parse_header(): Fixed parsing of header parameters to
  support unusual filenames (such as those containing semi-colons) in
  Content-Disposition headers.

- Issue #4384: Added logging integration with warnings module using
  captureWarnings(). This change includes a NullHandler which does nothing;
  it will be of use to library developers who want to avoid the "No handlers
  could be found for logger XXX" message which can appear if the library user
  doesn't configure logging.

- Issue #3741: DISTUTILS_USE_SDK set causes msvc9compiler.py to raise an
  exception.

- Issue #4529: fix the parser module's validation of try-except-finally
  statements.

- Issue #4458: getopt.gnu_getopt() now recognizes a single "-" as an argument,
  not a malformed option.

- Added the subprocess.check_output() convenience function to get output
  from a subprocess on success or raise an exception on error.

- Issue #4542: On Windows, binascii.crc32 still accepted str as binary input;
  the corresponding tests now pass.

- Issue #4537: webbrowser.UnixBrowser would fail to open the browser because
  it was calling the wrong open() function.

- Issue #1055234: cgi.parse_header(): Fixed parsing of header parameters to
  support unusual filenames (such as those containing semi-colons) in
  Content-Disposition headers.

- Issue #4861: ctypes.util.find_library(): Robustify. Fix library detection on
  biarch systems. Try to rely on ldconfig only, without using objdump and gcc.

- Issue #5104: The socket module now raises OverflowError when 16-bit port and
  protocol numbers are supplied outside the allowed 0-65536 range on bind()
  and getservbyport().

- Windows locale mapping updated to Vista.

Tools/Demos
-----------

- Issue #4704: remove use of cmp() in pybench, bump its version number to 2.1,
  and make it 2.6-compatible.

- Ttk demos added in Demo/tkinter/ttk/

- Issue #4677: add two list comprehension tests to pybench.


Build
-----

- Issue #6094: Build correctly with Subversion 1.7.

- Issue #5847: Remove -n switch on "Edit with IDLE" menu item.

- Issue #5726: Make Modules/ld_so_aix return the actual exit code of the
  linker, rather than always exit successfully. Patch by Floris Bruynooghe.

- Issue #4587: Add configure option --with-dbmliborder=db1:db2:... to specify
  the order that backends for the dbm extension are checked.

- Link the shared python library with $(MODLIBS).

- Issue #5134: Silence compiler warnings when compiling sqlite with VC++.

- Issue #4494: Fix build with Py_NO_ENABLE_SHARED on Windows.

- Issue #4895: Use _strdup on Windows CE.

- Issue #4472: "configure --enable-shared" now works on OSX

- Issues #4728 and #4060: WORDS_BIGEDIAN is now correct in Universal builds.

- Issue #4389: Add icon to the uninstall entry in "add-and-remove-programs".

- Issue #4289: Remove Cancel button from AdvancedDlg.

- Issue #1656675: Register a drop handler for .py* files on Windows.

- Issue #4120: Exclude manifest from extension modules in VS2008.

- Issue #4091: Install pythonxy.dll in system32 again.

- Issue #4018: Disable "for me" installations on Vista.

- Issue #3758: Add ``patchcheck`` build target to .PHONY.

- Issue #4204: Fixed module build errors on FreeBSD 4.


C-API
-----

- Issue #6624: yArg_ParseTuple with "s" format when parsing argument with
  NUL: Bogus TypeError detail string.

- Issue #5175: PyLong_AsUnsignedLongLong now raises OverflowError
  for negative arguments.  Previously, it raised TypeError.

- Issue #4720: The format for PyArg_ParseTupleAndKeywords can begin with '|'.

- Issue #3632: from the gdb debugger, the 'pyo' macro can now be called when
  the GIL is released, or owned by another thread.

- Issue #4122: On Windows, fix a compilation error when using the
  Py_UNICODE_ISSPACE macro in an extension module.


Extension Modules
-----------------

- Issue #3745: Fix hashlib to always reject unicode and non buffer-api
  supporting objects as input no matter how it was compiled (built in
  implementations or external openssl library).

- Issue #4397: Fix occasional test_socket failure on OS X.

- Issue #4279: Fix build of parsermodule under Cygwin.

- Issue #4751: hashlib now releases the GIL when hashing large buffers
  (with a hardwired threshold of 2048 bytes), allowing better parallelization
  on multi-CPU systems. Contributed by Lukas Lueg (ebfe) and Victor Stinner.

- Issue #4051: Prevent conflict of UNICODE macros in cPickle.

- Issue #4738: Each zlib object now has a separate lock, allowing to compress
  or decompress several streams at once on multi-CPU systems. Also, the GIL
  is now released when computing the CRC of a large buffer. Patch by ebfe.

- Issue #4228: Pack negative values the same way as 2.4 in struct's L format.

- Issue #1040026: Fix os.times result on systems where HZ is incorrect.

- Issues #3167, #3682: Fix test_math failures for log, log10 on Solaris,
  OpenBSD.

- Issue #4583: array.array would not always prohibit resizing when a buffer
  has been exported, resulting in an interpreter crash when accessing the
  buffer.


- Issue #5228: Make functools.partial objects can now be pickled.

Tests
-----

- Issue #6152: New option '-j'/'--multiprocess' for regrtest allows running
  regression tests in parallel, shortening the total runtime.

- Issue #5450: Moved tests involving loading tk from Lib/test/test_tcl to
  Lib/tkinter/test/test_tkinter/test_loadtk. With this, these tests demonstrate
  the same behaviour as test_ttkguionly (and now also test_tk) which is to
  skip the tests if DISPLAY is defined but can't be used.

- regrtest no longer treats ImportError as equivalent to SkipTest.  Imports
  that should cause a test to be skipped are now done using import_module
  from test support, which does the conversion.

- Issue #5083: New 'gui' resource for regrtest.


Docs
----


**(For information about older versions, consult the HISTORY file.)**