Misc/NEWS

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

(editors: check NEWS.help for information about editing NEWS using ReST.)

What's New in Python 2.5 release candidate 1?
=============================================

*Release date: XX-AUG-2006*

Core and builtins
-----------------

- Bug #1524310: Properly report errors from FindNextFile in os.listdir.

- Patch #1232023: Stop including current directory in search
  path on Windows.

- Fix some potential crashes found with failmalloc.

- Fix warnings reported by Klocwork's static analysis tool.

- Bug #1512814, Fix incorrect lineno's when code within a function
  had more than 255 blank lines.

- Patch #1521179: Python now accepts the standard options ``--help`` and
  ``--version`` as well as ``/?`` on Windows.

- Bug #1520864: unpacking singleton tuples in for loop (for x, in) work
  again.  Fixing this problem required changing the .pyc magic number.
  This means that .pyc files generated before 2.5c1 will be regenerated.

- Bug #1524317:  Compiling Python ``--without-threads`` failed.
  The Python core compiles again then, and, in a build without threads, the
  new ``sys._current_frames()`` returns a dictionary with one entry,
  mapping the faux "thread id" 0 to the current frame.

- Bug #1525447: build on MacOS X on a case-sensitive filesystem.
  

Library
-------

- Bug #1459963: urllib and urllib2 now normalize HTTP header names correctly
  with title().

- Patch #1525766: In pkgutil.walk_packages, correctly pass the onerror callback
  to recursive calls and call it with the failing package name.

- Bug #1525817: Don't truncate short lines in IDLE's tool tips.

- Patch #1515343: Fix printing of deprecated string exceptions with a
  value in the traceback module.

- Resync optparse with Optik 1.5.3: minor tweaks for/to tests.

- Patch #1524429: Use repr() instead of backticks in Tkinter again.

- Bug #1520914: Change time.strftime() to accept a zero for any position in its
  argument tuple.  For arguments where zero is illegal, the value is forced to
  the minimum value that is correct.  This is to support an undocumented but
  common way people used  to fill in inconsequential information in the time
  tuple pre-2.4.

- Patch #1220874: Update the binhex module for Mach-O.

- The email package has improved RFC 2231 support, specifically for
  recognizing the difference between encoded (name*0*=<blah>) and non-encoded
  (name*0=<blah>) parameter continuations.  This may change the types of
  values returned from email.message.Message.get_param() and friends.
  Specifically in some cases where non-encoded continuations were used,
  get_param() used to return a 3-tuple of (None, None, string) whereas now it
  will just return the string (since non-encoded continuations don't have
  charset and language parts).

  Also, whereas % values were decoded in all parameter continuations, they are
  now only decoded in encoded parameter parts.

- Bug #1517990: IDLE keybindings on MacOS X now work correctly

- Bug #1517996: IDLE now longer shows the default Tk menu when a
  path browser, class browser or debugger is the frontmost window on MacOS X


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

- Patch #1448199: Release interpreter lock in _winreg.ConnectRegistry.

- Patch #1521817: Index range checking on ctypes arrays containing
  exactly one element enabled again.  This allows iterating over these
  arrays, without the need to check the array size before.

- Bug #1521375: When the code in ctypes.util.find_library was
  run with root privileges, it could overwrite or delete
  /dev/null in certain cases; this is now fixed.

- Bug #1467450: On Mac OS X 10.3, RTLD_GLOBAL is now used as the
  default mode for loading shared libraries in ctypes.

- Because of a misspelled preprocessor symbol, ctypes was always
  compiled without thread support; this is now fixed.

Tests
-----

- Bug #1501330: Change test_ossaudiodev to be much more tolerant in terms of
  how long the test file should take to play.  Now accepts taking 2.93 secs
  (exact time) +/- 10% instead of the hard-coded 3.1 sec.


What's New in Python 2.5 beta 2?
================================

*Release date: 11-JUL-2006*

Core and builtins
-----------------

- Bug #1441486: The literal representation of -(sys.maxint - 1)
  again evaluates to a int object, not a long.

- Bug #1501934: The scope of global variables that are locally assigned
  using augmented assignment is now correctly determined.

- Bug #927248: Recursive method-wrapper objects can now safely
  be released.

- Bug #1417699: Reject locale-specific decimal point in float()
  and atof().

- Bug #1511381: codec_getstreamcodec() in codec.c is corrected to
  omit a default "error" argument for NULL pointer.  This allows
  the parser to take a codec from cjkcodecs again.

- Bug #1519018: 'as' is now validated properly in import statements.

- On 64 bit systems, int literals that use less than 64 bits are
  now ints rather than longs.

- Bug #1512814, Fix incorrect lineno's when code at module scope
  started after line 256.

- New function ``sys._current_frames()`` returns a dict mapping thread
  id to topmost thread stack frame.  This is for expert use, and is
  especially useful for debugging application deadlocks.  The functionality
  was previously available in Fazal Majid's ``threadframe`` extension
  module, but it wasn't possible to do this in a wholly threadsafe way from
  an extension.

Library
-------

- Patch #1519566: Update turtle demo, make begin_fill idempotent.

- Bug #1508010: msvccompiler now requires the DISTUTILS_USE_SDK
  environment variable to be set in order to the SDK environment
  for finding the compiler, include files, etc.

- Bug #1515998: Properly generate logical ids for files in bdist_msi.

- warnings.py now ignores ImportWarning by default

- string.Template() now correctly handles tuple-values. Previously,
  multi-value tuples would raise an exception and single-value tuples would
  be treated as the value they contain, instead.

- Bug #822974: Honor timeout in telnetlib.{expect,read_until}
  even if some data are received.

- Bug #1267547: Put proper recursive setup.py call into the
  spec file generated by bdist_rpm.

- Bug #1514693: Update turtle's heading when switching between
  degrees and radians.

- Reimplement turtle.circle using a polyline, to allow correct
  filling of arcs.

- Bug #1514703: Only setup canvas window in turtle when the canvas
  is created.

- Bug #1513223: .close() of a _socketobj now releases the underlying
  socket again, which then gets closed as it becomes unreferenced.

- Bug #1504333: Make sgmllib support angle brackets in quoted
  attribute values.

- Bug #853506: Fix IPv6 address parsing in unquoted attributes in
  sgmllib ('[' and ']' were not accepted).

- Fix a bug in the turtle module's end_fill function.

- Bug #1510580: The 'warnings' module improperly required that a Warning
  category be either a types.ClassType and a subclass of Warning.  The proper
  check is just that it is a subclass with Warning as the documentation states.

- The compiler module now correctly compiles the new try-except-finally
  statement (bug #1509132).

- The wsgiref package is now installed properly on Unix.

- A bug was fixed in logging.config.fileConfig() which caused a crash on
  shutdown when fileConfig() was called multiple times.

- The sqlite3 module did cut off data from the SQLite database at the first
  null character before sending it to a custom converter. This has been fixed
  now.

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

- #1494314: Fix a regression with high-numbered sockets in 2.4.3. This
  means that select() on sockets > FD_SETSIZE (typically 1024) work again.
  The patch makes sockets use poll() internally where available.

- Assigning None to pointer type fields in ctypes structures possible
  overwrote the wrong fields, this is fixed now.

- Fixed a segfault in _ctypes when ctypes.wintypes were imported
  on non-Windows platforms.

- Bug #1518190: The ctypes.c_void_p constructor now accepts any
  integer or long, without range checking.

- Patch #1517790: It is now possible to use custom objects in the ctypes
  foreign function argtypes sequence as long as they provide a from_param
  method, no longer is it required that the object is a ctypes type.

- The '_ctypes' extension module now works when Python is configured
  with the --without-threads option.

- Bug #1513646: os.access on Windows now correctly determines write
  access, again.

- Bug #1512695: cPickle.loads could crash if it was interrupted with
  a KeyboardInterrupt.

- Bug #1296433: parsing XML with a non-default encoding and
  a CharacterDataHandler could crash the interpreter in pyexpat.

- Patch #1516912: improve Modules support for OpenVMS.

Build
-----

- Automate Windows build process for the Win64 SSL module.

- 'configure' now detects the zlib library the same way as distutils.
  Previously, the slight difference could cause compilation errors of the
  'zlib' module on systems with more than one version of zlib.

- The MSI compileall step was fixed to also support a TARGETDIR
  with spaces in it.

- Bug #1517388: sqlite3.dll is now installed on Windows independent
  of Tcl/Tk.

- Bug #1513032: 'make install' failed on FreeBSD 5.3 due to lib-old
  trying to be installed even though it's empty.

Tests
-----

- Call os.waitpid() at the end of tests that spawn child processes in order
  to minimize resources (zombies).

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

- Cover ImportWarning, PendingDeprecationWarning and simplefilter() in the
  documentation for the warnings module.

- Patch #1509163: MS Toolkit Compiler no longer available.

- Patch #1504046: Add documentation for xml.etree.

What's New in Python 2.5 beta 1?
================================

*Release date: 20-JUN-2006*

Core and builtins
-----------------

- Patch #1507676: Error messages returned by invalid abstract object operations
  (such as iterating over an integer) have been improved and now include the
  type of the offending object to help with debugging.

- Bug #992017: A classic class that defined a __coerce__() method that returned
  its arguments swapped would infinitely recurse and segfault the interpreter.

- Fix the socket tests so they can be run concurrently.

- Removed 5 integers from C frame objects (PyFrameObject).
  f_nlocals, f_ncells, f_nfreevars, f_stack_size, f_restricted.

- Bug #532646: object.__call__() will continue looking for the __call__
  attribute on objects until one without one is found.  This leads to recursion
  when you take a class and set its __call__ attribute to an instance of the
  class.  Originally fixed for classic classes, but this fix is for new-style.
  Removes the infinite_rec_3 crasher.

- The string and unicode methods startswith() and endswith() now accept
  a tuple of prefixes/suffixes to look for. Implements RFE #1491485.

- Buffer objects, at the C level, never used the char buffer
  implementation even when the char buffer for the wrapped object was
  explicitly requested (originally returned the read or write buffer).
  Now a TypeError is raised if the char buffer is not present but is
  requested.

- Patch #1346214: Statements like "if 0: suite" are now again optimized
  away like they were in Python 2.4.

- Builtin exceptions are now full-blown new-style classes instead of
  instances pretending to be classes, which speeds up exception handling
  by about 80% in comparison to 2.5a2.

- Patch #1494554: Update unicodedata.numeric and unicode.isnumeric to
  Unicode 4.1.

- Patch #921466: sys.path_importer_cache is now used to cache valid and
  invalid file paths for the built-in import machinery which leads to
  fewer open calls on startup.

- Patch #1442927: ``long(str, base)`` is now up to 6x faster for non-power-
  of-2 bases.  The largest speedup is for inputs with about 1000 decimal
  digits.  Conversion from non-power-of-2 bases remains quadratic-time in
  the number of input digits (it was and remains linear-time for bases
  2, 4, 8, 16 and 32).

- Bug #1334662: ``int(string, base)`` could deliver a wrong answer
  when ``base`` was not 2, 4, 8, 10, 16 or 32, and ``string`` represented
  an integer close to ``sys.maxint``.  This was repaired by patch
  #1335972, which also gives a nice speedup.

- Patch #1337051: reduced size of frame objects.

- PyErr_NewException now accepts a tuple of base classes as its
  "base" parameter.

- Patch #876206: function call speedup by retaining allocated frame
  objects.

- Bug #1462152: file() now checks more thoroughly for invalid mode
  strings and removes a possible "U" before passing the mode to the
  C library function.

- Patch #1488312, Fix memory alignment problem on SPARC in unicode

- Bug #1487966: Fix SystemError with conditional expression in assignment

- WindowsError now has two error code attributes: errno, which carries
  the error values from errno.h, and winerror, which carries the error
  values from winerror.h. Previous versions put the winerror.h values
  (from GetLastError()) into the errno attribute.

- Patch #1475845: Raise IndentationError for unexpected indent.

- Patch #1479181: split open() and file() from being aliases for each other.

- Patch #1497053 & bug #1275608: Exceptions occurring in ``__eq__()``
  methods were always silently ignored by dictionaries when comparing keys.
  They are now passed through (except when using the C API function
  ``PyDict_GetItem()``, whose semantics did not change).

- Bug #1456209: In some obscure cases it was possible for a class with a
  custom ``__eq__()`` method to confuse dict internals when class instances
  were used as a dict's keys and the ``__eq__()`` method mutated the dict.
  No, you don't have any code that did this ;-)

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

- Bug #1295808: expat symbols should be namespaced in pyexpat

- Patch #1462338: Upgrade pyexpat to expat 2.0.0

- Change binascii.hexlify to accept a read-only buffer instead of only a char
  buffer and actually follow its documentation.

- Fixed a potentially invalid memory access of CJKCodecs' shift-jis decoder.

- Patch #1478788 (modified version): The functional extension module has
  been renamed to _functools and a functools Python wrapper module added.
  This provides a home for additional function related utilities that are
  not specifically about functional programming. See PEP 309.

- Patch #1493701: performance enhancements for struct module.

- Patch #1490224: time.altzone is now set correctly on Cygwin.

- Patch #1435422: zlib's compress and decompress objects now have a
  copy() method.

- Patch #1454481: thread stack size is now tunable at runtime for thread
  enabled builds on Windows and systems with Posix threads support.

- On Win32, os.listdir now supports arbitrarily-long Unicode path names
  (up to the system limit of 32K characters).

- Use Win32 API to implement os.{access,chdir,chmod,mkdir,remove,rename,rmdir,utime}.
  As a result, these functions now raise WindowsError instead of OSError.

- ``time.clock()`` on Win64 should use the high-performance Windows
  ``QueryPerformanceCounter()`` now (as was already the case on 32-bit
  Windows platforms).

- Calling Tk_Init twice is refused if the first call failed as that
  may deadlock.

- bsddb: added the DB_ARCH_REMOVE flag and fixed db.DBEnv.log_archive() to
  accept it without potentially using an uninitialized pointer.

- bsddb: added support for the DBEnv.log_stat() and DBEnv.lsn_reset() methods
  assuming BerkeleyDB >= 4.0 and 4.4 respectively.  [pybsddb project SF
  patch numbers 1494885 and 1494902]

- bsddb: added an interface for the BerkeleyDB >= 4.3 DBSequence class.
  [pybsddb project SF patch number 1466734]

- bsddb: fix DBCursor.pget() bug with keyword argument names when no data
  parameter is supplied.  [SF pybsddb bug #1477863]

- bsddb: the __len__ method of a DB object has been fixed to return correct
  results.  It could previously incorrectly return 0 in some cases.
  Fixes SF bug 1493322 (pybsddb bug 1184012).

- bsddb: the bsddb.dbtables Modify method now raises the proper error and
  aborts the db transaction safely when a modifier callback fails.
  Fixes SF python patch/bug #1408584.

- bsddb: multithreaded DB access using the simple bsddb module interface
  now works reliably.  It has been updated to use automatic BerkeleyDB
  deadlock detection and the bsddb.dbutils.DeadlockWrap wrapper to retry
  database calls that would previously deadlock. [SF python bug #775414]

- Patch #1446489: add support for the ZIP64 extensions to zipfile.

- Patch #1506645: add Python wrappers for the curses functions
  is_term_resized, resize_term and resizeterm.

Library
-------

- Patch #815924: Restore ability to pass type= and icon= in tkMessageBox
  functions.

- Patch #812986: Update turtle output even if not tracing.

- Patch #1494750: Destroy master after deleting children in
  Tkinter.BaseWidget.

- Patch #1096231: Add ``default`` argument to Tkinter.Wm.wm_iconbitmap.

- Patch #763580: Add name and value arguments to Tkinter variable
  classes.

- Bug #1117556: SimpleHTTPServer now tries to find and use the system's
  mime.types file for determining MIME types.

- Bug #1339007: Shelf objects now don't raise an exception in their
  __del__ method when initialization failed.

- Patch #1455898: The MBCS codec now supports the incremental mode for
  double-byte encodings.

- ``difflib``'s ``SequenceMatcher.get_matching_blocks()`` was changed to
  guarantee that adjacent triples in the return list always describe
  non-adjacent blocks.  Previously, a pair of matching blocks could end
  up being described by multiple adjacent triples that formed a partition
  of the matching pair.

- Bug #1498146: fix optparse to handle Unicode strings in option help,
  description, and epilog.

- Bug #1366250: minor optparse documentation error.

- Bug #1361643: fix textwrap.dedent() so it handles tabs appropriately;
  clarify docs.

- The wsgiref package has been added to the standard library.

- The functions update_wrapper() and wraps() have been added to the functools
  module. These make it easier to copy relevant metadata from the original
  function when writing wrapper functions.

- The optional ``isprivate`` argument to ``doctest.testmod()``, and the
  ``doctest.is_private()`` function, both deprecated in 2.4, were removed.

- Patch #1359618: Speed up charmap encoder by using a trie structure
  for lookup.

- The functions in the ``pprint`` module now sort dictionaries by key
  before computing the display.  Before 2.5, ``pprint`` sorted a dictionary
  if and only if its display required more than one line, although that
  wasn't documented.  The new behavior increases predictability; e.g.,
  using ``pprint.pprint(a_dict)`` in a doctest is now reliable.

- Patch #1497027: try HTTP digest auth before basic auth in urllib2
  (thanks for J. J. Lee).

- Patch #1496206: improve urllib2 handling of passwords with respect to
  default HTTP and HTTPS ports.

- Patch #1080727: add "encoding" parameter to doctest.DocFileSuite.

- Patch #1281707: speed up gzip.readline.

- Patch #1180296: Two new functions were added to the locale module:
  format_string() to get the effect of  "format % items" but locale-aware,
  and currency() to format a monetary number with currency sign.

- Patch #1486962: Several bugs in the turtle Tk demo module were fixed
  and several features added, such as speed and geometry control.

- Patch #1488881: add support for external file objects in bz2 compressed
  tarfiles.

- Patch #721464: pdb.Pdb instances can now be given explicit stdin and
  stdout arguments, making it possible to redirect input and output
  for remote debugging.

- Patch #1484695: Update the tarfile module to version 0.8. This fixes
  a couple of issues, notably handling of long file names using the
  GNU LONGNAME extension.

- Patch #1478292. ``doctest.register_optionflag(name)`` shouldn't create a
  new flag when ``name`` is already the name of an option flag.

- Bug #1385040: don't allow "def foo(a=1, b): pass" in the compiler
  package.

- Patch #1472854: make the rlcompleter.Completer class usable on non-
  UNIX platforms.

- Patch #1470846: fix urllib2 ProxyBasicAuthHandler.

- Bug #1472827: correctly escape newlines and tabs in attribute values in
  the saxutils.XMLGenerator class.


Build
-----

- Bug #1502728: Correctly link against librt library on HP-UX.

- OpenBSD 3.9 is supported now.

- Patch #1492356: Port to Windows CE.

- Bug/Patch #1481770: Use .so extension for shared libraries on HP-UX for ia64.

- Patch #1471883: Add --enable-universalsdk.

C API
-----

Tests
-----

Tools
-----

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



What's New in Python 2.5 alpha 2?
=================================

*Release date: 27-APR-2006*

Core and builtins
-----------------

- Bug #1465834: 'bdist_wininst preinstall script support' was fixed
  by converting these apis from macros into exported functions again:

    PyParser_SimpleParseFile PyParser_SimpleParseString PyRun_AnyFile
    PyRun_AnyFileEx PyRun_AnyFileFlags PyRun_File PyRun_FileEx
    PyRun_FileFlags PyRun_InteractiveLoop PyRun_InteractiveOne
    PyRun_SimpleFile PyRun_SimpleFileEx PyRun_SimpleString
    PyRun_String Py_CompileString

- Under COUNT_ALLOCS, types are not necessarily immortal anymore.

- All uses of PyStructSequence_InitType have been changed to initialize
  the type objects only once, even if the interpreter is initialized
  multiple times.

- Bug #1454485, array.array('u') could crash the interpreter.  This was
  due to PyArgs_ParseTuple(args, 'u#', ...) trying to convert buffers (strings)
  to unicode when it didn't make sense.  'u#' now requires a unicode string.

- Py_UNICODE is unsigned.  It was always documented as unsigned, but
  due to a bug had a signed value in previous versions.

- Patch #837242: ``id()`` of any Python object always gives a positive
  number now, which might be a long integer. ``PyLong_FromVoidPtr`` and
  ``PyLong_AsVoidPtr`` have been changed accordingly.  Note that it has
  never been correct to implement a ``__hash()__`` method that returns the
  ``id()`` of an object:

      def __hash__(self):
          return id(self)  # WRONG

  because a hash result must be a (short) Python int but it was always
  possible for ``id()`` to return a Python long.  However, because ``id()``
  could return negative values before, on a 32-bit box an ``id()`` result
  was always usable as a hash value before this patch.  That's no longer
  necessarily so.

- Python on OS X 10.3 and above now uses dlopen() (via dynload_shlib.c)
  to load extension modules and now provides the dl module. As a result,
  sys.setdlopenflags() now works correctly on these systems. (SF patch
  #1454844)

- Patch #1463867: enhanced garbage collection to allow cleanup of cycles
  involving generators that have paused outside of any ``try`` or ``with``
  blocks.  (In 2.5a1, a paused generator that was part of a reference
  cycle could not be garbage collected, regardless of whether it was
  paused in a ``try`` or ``with`` block.)

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

- Patch #1191065: Fix preprocessor problems on systems where recvfrom
  is a macro.

- Bug #1467952: os.listdir() now correctly raises an error if readdir()
  fails with an error condition.

- Fixed bsddb.db.DBError derived exceptions so they can be unpickled.

- Bug #1117761: bsddb.*open() no longer raises an exception when using
  the cachesize parameter.

- Bug #1149413: bsddb.*open() no longer raises an exception when using
  a temporary db (file=None) with the 'n' flag to truncate on open.

- Bug #1332852: bsddb module minimum BerkeleyDB version raised to 3.3
  as older versions cause excessive test failures.

- Patch #1062014: AF_UNIX sockets under Linux have a special
  abstract namespace that is now fully supported.

Library
-------

- Bug #1223937: subprocess.CalledProcessError reports the exit status
  of the process using the returncode attribute, instead of
  abusing errno.

- Patch #1475231: ``doctest`` has a new ``SKIP`` option, which causes
  a doctest to be skipped (the code is not run, and the expected output
  or exception is ignored).

- Fixed contextlib.nested to cope with exceptions being raised and
  caught inside exit handlers.

- Updated optparse module to Optik 1.5.1 (allow numeric constants in
  hex, octal, or binary; add ``append_const`` action; keep going if
  gettext cannot be imported; added ``OptionParser.destroy()`` method;
  added ``epilog`` for better help generation).

- Bug #1473760: ``tempfile.TemporaryFile()`` could hang on Windows, when
  called from a thread spawned as a side effect of importing a module.

- The pydoc module now supports documenting packages contained in
  .zip or .egg files.

- The pkgutil module now has several new utility functions, such
  as ``walk_packages()`` to support working with packages that are either
  in the filesystem or zip files.

- The mailbox module can now modify and delete messages from
  mailboxes, in addition to simply reading them.  Thanks to Gregory
  K. Johnson for writing the code, and to the 2005 Google Summer of
  Code for funding his work.

- The ``__del__`` method of class ``local`` in module ``_threading_local``
  returned before accomplishing any of its intended cleanup.

- Patch #790710: Add breakpoint command lists in pdb.

- Patch #1063914: Add Tkinter.Misc.clipboard_get().

- Patch #1191700: Adjust column alignment in bdb breakpoint lists.

- SimpleXMLRPCServer relied on the fcntl module, which is unavailable on
  Windows. Bug #1469163.

- The warnings, linecache, inspect, traceback, site, and doctest modules
  were updated to work correctly with modules imported from zipfiles or
  via other PEP 302 __loader__ objects.

- Patch #1467770: Reduce usage of subprocess._active to processes which
  the application hasn't waited on.

- Patch #1462222: Fix Tix.Grid.

- Fix exception when doing glob.glob('anything*/')

- The pstats.Stats class accepts an optional stream keyword argument to
  direct output to an alternate file-like object.

Build
-----

- The Makefile now has a reindent target, which runs reindent.py on
  the library.

- Patch #1470875: Building Python with MS Free Compiler

- Patch #1161914: Add a python-config script.

- Patch #1324762:Remove ccpython.cc; replace --with-cxx with
  --with-cxx-main. Link with C++ compiler only if --with-cxx-main was
  specified. (Can be overridden by explicitly setting LINKCC.) Decouple
  CXX from --with-cxx-main, see description in README.

- Patch #1429775: Link extension modules with the shared libpython.

- Fixed a libffi build problem on MIPS systems.

- ``PyString_FromFormat``, ``PyErr_Format``, and ``PyString_FromFormatV``
  now accept formats "%u" for unsigned ints, "%lu" for unsigned longs,
  and "%zu" for unsigned integers of type ``size_t``.

Tests
-----

- test_contextlib now checks contextlib.nested can cope with exceptions
  being raised and caught inside exit handlers.

- test_cmd_line now checks operation of the -m and -c command switches

- The test_contextlib test in 2.5a1 wasn't actually run unless you ran
  it separately and by hand.  It also wasn't cleaning up its changes to
  the current Decimal context.

- regrtest.py now has a -M option to run tests that test the new limits of
  containers, on 64-bit architectures. Running these tests is only sensible
  on 64-bit machines with more than two gigabytes of memory. The argument
  passed is the maximum amount of memory for the tests to use.

Tools
-----

- Added the Python benchmark suite pybench to the Tools/ directory;
  contributed by Marc-Andre Lemburg.

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

- Patch #1473132: Improve docs for ``tp_clear`` and ``tp_traverse``.

- PEP 343: Added Context Types section to the library reference
  and attempted to bring other PEP 343 related documentation into
  line with the implementation and/or python-dev discussions.

- Bug #1337990: clarified that ``doctest`` does not support examples
  requiring both expected output and an exception.


What's New in Python 2.5 alpha 1?
=================================

*Release date: 05-APR-2006*

Core and builtins
-----------------

- PEP 338: -m command line switch now delegates to runpy.run_module
  allowing it to support modules in packages and zipfiles

- On Windows, .DLL is not an accepted file name extension for
  extension modules anymore; extensions are only found if they
  end in .PYD.

- Bug #1421664: sys.stderr.encoding is now set to the same value as
  sys.stdout.encoding.

- __import__ accepts keyword arguments.

- Patch #1460496: round() now accepts keyword arguments.

- Fixed bug #1459029 - unicode reprs were double-escaped.

- Patch #1396919: The system scope threads are reenabled on FreeBSD
  5.4 and later versions.

- Bug #1115379: Compiling a Unicode string with an encoding declaration
  now gives a SyntaxError.

- Previously, Python code had no easy way to access the contents of a
  cell object. Now, a ``cell_contents`` attribute has been added
  (closes patch #1170323).

- Patch #1123430: Python's small-object allocator now returns an arena to
  the system ``free()`` when all memory within an arena becomes unused
  again.  Prior to Python 2.5, arenas (256KB chunks of memory) were never
  freed.  Some applications will see a drop in virtual memory size now,
  especially long-running applications that, from time to time, temporarily
  use a large number of small objects.  Note that when Python returns an
  arena to the platform C's ``free()``, there's no guarantee that the
  platform C library will in turn return that memory to the operating system.
  The effect of the patch is to stop making that impossible, and in tests it
  appears to be effective at least on Microsoft C and gcc-based systems.
  Thanks to Evan Jones for hard work and patience.

- Patch #1434038: property() now uses the getter's docstring if there is
  no "doc" argument given. This makes it possible to legitimately use
  property() as a decorator to produce a read-only property.

- PEP 357, patch 1436368: add an __index__ method to int/long and a matching
  nb_index slot to the PyNumberMethods struct.  The slot is consulted instead
  of requiring an int or long in slicing and a few other contexts, enabling
  other objects (e.g. Numeric Python's integers) to be used as slice indices.

- Fixed various bugs reported by Coverity's Prevent tool.

- PEP 352, patch #1104669: Make exceptions new-style objects.  Introduced the
  new exception base class, BaseException, which has a new message attribute.
  KeyboardInterrupt and SystemExit to directly inherit from BaseException now.
  Raising a string exception now raises a DeprecationWarning.

- Patch #1438387, PEP 328: relative and absolute imports. Imports can now be
  explicitly relative, using 'from .module import name' to mean 'from the same
  package as this module is in. Imports without dots still default to the
  old relative-then-absolute, unless 'from __future__ import
  absolute_import' is used.

- Properly check if 'warnings' raises an exception (usually when a filter set
  to "error" is triggered) when raising a warning for raising string
  exceptions.

- CO_GENERATOR_ALLOWED is no longer defined. This behavior is the default.
  The name was removed from Include/code.h.

- PEP 308: conditional expressions were added: (x if cond else y).

- Patch 1433928:
  - The copy module now "copies" function objects (as atomic objects).
  - dict.__getitem__ now looks for a __missing__ hook before raising
    KeyError.

- PEP 343: with statement implemented. Needs ``from __future__ import
  with_statement``. Use of 'with' as a variable will generate a warning.
  Use of 'as' as a variable will also generate a warning (unless it's
  part of an import statement).
  The following objects have __context__ methods:
  - The built-in file type.
  - The thread.LockType type.
  - The following types defined by the threading module:
    Lock, RLock, Condition, Semaphore, BoundedSemaphore.
  - The decimal.Context class.

- Fix the encodings package codec search function to only search
  inside its own package. Fixes problem reported in patch #1433198.

  Note: Codec packages should implement and register their own
  codec search function. PEP 100 has the details.

- PEP 353: Using ``Py_ssize_t`` as the index type.

- ``PYMALLOC_DEBUG`` builds now add ``4*sizeof(size_t)`` bytes of debugging
  info to each allocated block, since the ``Py_ssize_t`` changes (PEP 353)
  now allow Python to make use of memory blocks exceeding 2**32 bytes for
  some purposes on 64-bit boxes.  A ``PYMALLOC_DEBUG`` build was limited
  to 4-byte allocations before.

- Patch #1400181, fix unicode string formatting to not use the locale.
  This is how string objects work.  u'%f' could use , instead of .
  for the decimal point.  Now both strings and unicode always use periods.

- Bug #1244610, #1392915, fix build problem on OpenBSD 3.7 and 3.8.
  configure would break checking curses.h.

- Bug #959576: The pwd module is now builtin. This allows Python to be
  built on UNIX platforms without $HOME set.

- Bug #1072182, fix some potential problems if characters are signed.

- Bug #889500, fix line number on SyntaxWarning for global declarations.

- Bug #1378022, UTF-8 files with a leading BOM crashed the interpreter.

- Support for converting hex strings to floats no longer works.
  This was not portable.  float('0x3') now raises a ValueError.

- Patch #1382163: Expose Subversion revision number to Python.  New C API
  function Py_GetBuildNumber().  New attribute sys.subversion.  Build number
  is now displayed in interactive prompt banner.

- Implementation of PEP 341 - Unification of try/except and try/finally.
  "except" clauses can now be written together with a "finally" clause in
  one try statement instead of two nested ones.  Patch #1355913.

- Bug #1379994: Builtin unicode_escape and raw_unicode_escape codec
  now encodes backslash correctly.

- Patch #1350409: Work around signal handling bug in Visual Studio 2005.

- Bug #1281408: Py_BuildValue now works correctly even with unsigned longs
  and long longs.

- SF Bug #1350188, "setdlopenflags" leads to crash upon "import"
  It was possible for dlerror() to return a NULL pointer, so
  it will now use a default error message in this case.

- Replaced most Unicode charmap codecs with new ones using the
  new Unicode translate string feature in the builtin charmap
  codec; the codecs were created from the mapping tables available
  at ftp.unicode.org and contain a few updates (e.g. the Mac OS
  encodings now include a mapping for the Apple logo)

- Added a few more codecs for Mac OS encodings

- Sped up some Unicode operations.

- A new AST parser implementation was completed. The abstract
  syntax tree is available for read-only (non-compile) access
  to Python code; an _ast module was added.

- SF bug #1167751: fix incorrect code being produced for generator expressions.
  The following code now raises a SyntaxError:  foo(a = i for i in range(10))

- SF Bug #976608: fix SystemError when mtime of an imported file is -1.

- SF Bug #887946: fix segfault when redirecting stdin from a directory.
  Provide a warning when a directory is passed on the command line.

- Fix segfault with invalid coding.

- SF bug #772896: unknown encoding results in MemoryError.

- All iterators now have a Boolean value of True.  Formerly, some iterators
  supported a __len__() method which evaluated to False when the iterator
  was empty.

- On 64-bit platforms, when __len__() returns a value that cannot be
  represented as a C int, raise OverflowError.

- test__locale is skipped on OS X < 10.4 (only partial locale support is
  present).

- SF bug #893549: parsing keyword arguments was broken with a few format
  codes.

- Changes donated by Elemental Security to make it work on AIX 5.3
  with IBM's 64-bit compiler (SF patch #1284289).  This also closes SF
  bug #105470: test_pwd fails on 64bit system (Opteron).

- Changes donated by Elemental Security to make it work on HP-UX 11 on
  Itanium2 with HP's 64-bit compiler (SF patch #1225212).

- Disallow keyword arguments for type constructors that don't use them
  (fixes bug #1119418).

- Forward UnicodeDecodeError into SyntaxError for source encoding errors.

- SF bug #900092: When tracing (e.g. for hotshot), restore 'return' events for
  exceptions that cause a function to exit.

- The implementation of set() and frozenset() was revised to use its
  own internal data structure.  Memory consumption is reduced by 1/3
  and there are modest speed-ups as well.  The API is unchanged.

- SF bug #1238681:  freed pointer is used in longobject.c:long_pow().

- SF bug #1229429: PyObject_CallMethod failed to decrement some
  reference counts in some error exit cases.

- SF bug #1185883:  Python's small-object memory allocator took over
  a block managed by the platform C library whenever a realloc specified
  a small new size.  However, there's no portable way to know then how
  much of the address space following the pointer is valid, so there's no
  portable way to copy data from the C-managed block into Python's
  small-object space without risking a memory fault.  Python's small-object
  realloc now leaves such blocks under the control of the platform C
  realloc.

- SF bug #1232517: An overflow error was not detected properly when
  attempting to convert a large float to an int in os.utime().

- SF bug #1224347: hex longs now print with lowercase letters just
  like their int counterparts.

- SF bug #1163563: the original fix for bug #1010677 ("thread Module
  Breaks PyGILState_Ensure()") broke badly in the case of multiple
  interpreter states; back out that fix and do a better job (see
  http://mail.python.org/pipermail/python-dev/2005-June/054258.html
  for a longer write-up of the problem).

- SF patch #1180995: marshal now uses a binary format by default when
  serializing floats.

- SF patch #1181301: on platforms that appear to use IEEE 754 floats,
  the routines that promise to produce IEEE 754 binary representations
  of floats now simply copy bytes around.

- bug #967182: disallow opening files with 'wU' or 'aU' as specified by PEP
  278.

- patch #1109424: int, long, float, complex, and unicode now check for the
  proper magic slot for type conversions when subclassed.  Previously the
  magic slot was ignored during conversion.  Semantics now match the way
  subclasses of str always behaved.  int/long/float, conversion of an instance
  to the base class has been moved to the proper nb_* magic slot and out of
  PyNumber_*().
  Thanks Walter D�rwald.

- Descriptors defined in C with a PyGetSetDef structure, where the setter is
  NULL, now raise an AttributeError when attempting to set or delete the
  attribute.  Previously a TypeError was raised, but this was inconsistent
  with the equivalent pure-Python implementation.

- It is now safe to call PyGILState_Release() before
  PyEval_InitThreads() (note that if there is reason to believe there
  are multiple threads around you still must call PyEval_InitThreads()
  before using the Python API; this fix is for extension modules that
  have no way of knowing if Python is multi-threaded yet).

- Typing Ctrl-C whilst raw_input() was waiting in a build with threads
  disabled caused a crash.

- Bug #1165306: instancemethod_new allowed the creation of a method
  with im_class == im_self == NULL, which caused a crash when called.

- Move exception finalisation later in the shutdown process - this
  fixes the crash seen in bug #1165761

- Added two new builtins, any() and all().

- Defining a class with empty parentheses is now allowed
  (e.g., ``class C(): pass`` is no longer a syntax error).
  Patch #1176012 added support to the 'parser' module and 'compiler' package
  (thanks to logistix for that added support).

- Patch #1115086: Support PY_LONGLONG in structmember.

- Bug #1155938: new style classes did not check that __init__() was
  returning None.

- Patch #802188: Report characters after line continuation character
  ('\') with a specific error message.

- Bug #723201: Raise a TypeError for passing bad objects to 'L' format.

- Bug #1124295: the __name__ attribute of file objects was
  inadvertently made inaccessible in restricted mode.

- Bug #1074011: closing sys.std{out,err} now causes a flush() and
  an ferror() call.

- min() and max() now support key= arguments with the same meaning as in
  list.sort().

- The peephole optimizer now performs simple constant folding in expressions:
      (2+3) --> (5).

- set and frozenset objects can now be marshalled.  SF #1098985.

- Bug #1077106: Poor argument checking could cause memory corruption
  in calls to os.read().

- The parser did not complain about future statements in illegal
  positions.  It once again reports a syntax error if a future
  statement occurs after anything other than a doc string.

- Change the %s format specifier for str objects so that it returns a
  unicode instance if the argument is not an instance of basestring and
  calling __str__ on the argument returns a unicode instance.

- Patch #1413181:  changed ``PyThreadState_Delete()`` to forget about the
  current thread state when the auto-GIL-state machinery knows about
  it (since the thread state is being deleted, continuing to remember it
  can't help, but can hurt if another thread happens to get created with
  the same thread id).

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

- Patch #1380952: fix SSL objects timing out on consecutive read()s

- Patch #1309579: wait3 and wait4 were added to the posix module.

- Patch #1231053: The audioop module now supports encoding/decoding of alaw.
  In addition, the existing ulaw code was updated.

- RFE #567972: Socket objects' family, type and proto properties are
  now exposed via new attributes.

- Everything under lib-old was removed.  This includes the following modules:
    Para, addpack, cmp, cmpcache, codehack, dircmp, dump, find, fmt, grep,
    lockfile, newdir, ni, packmail, poly, rand, statcache, tb, tzparse,
    util, whatsound, whrandom, zmod

- The following modules were removed:  regsub, reconvert, regex, regex_syntax.

- re and sre were swapped, so help(re) provides full help.  importing sre
  is deprecated.  The undocumented re.engine variable no longer exists.

- Bug #1448490: Fixed a bug that ISO-2022 codecs could not handle
  SS2 (single-shift 2) escape sequences correctly.

- The unicodedata module was updated to the 4.1 version of the Unicode
  database. The 3.2 version is still available as unicodedata.db_3_2_0
  for applications that require this specific version (such as IDNA).

- The timing module is no longer built by default.  It was deprecated
  in PEP 4 in Python 2.0 or earlier.

- Patch 1433928: Added a new type, defaultdict, to the collections module.
  This uses the new __missing__ hook behavior added to dict (see above).

- Bug #854823: socketmodule now builds on Sun platforms even when
  INET_ADDRSTRLEN is not defined.

- Patch #1393157: os.startfile() now has an optional argument to specify
  a "command verb" to invoke on the file.

- Bug #876637, prevent stack corruption when socket descriptor
  is larger than FD_SETSIZE.

- Patch #1407135, bug #1424041: harmonize mmap behavior of anonymous memory.
  mmap.mmap(-1, size) now returns anonymous memory in both Unix and Windows.
  mmap.mmap(0, size) should not be used on Windows for anonymous memory.

- Patch #1422385: The nis module now supports access to domains other
  than the system default domain.

- Use Win32 API to implement os.stat/fstat. As a result, subsecond timestamps
  are reported, the limit on path name lengths is removed, and stat reports
  WindowsError now (instead of OSError).

- Add bsddb.db.DBEnv.set_tx_timestamp allowing time based database recovery.

- Bug #1413192, fix seg fault in bsddb if a transaction was deleted
  before the env.

- Patch #1103116: Basic AF_NETLINK support.

- Bug #1402308, (possible) segfault when using mmap.mmap(-1, ...)

- Bug #1400822, _curses over{lay,write} doesn't work when passing 6 ints.
  Also fix ungetmouse() which did not accept arguments properly.
  The code now conforms to the documented signature.

- Bug #1400115, Fix segfault when calling curses.panel.userptr()
  without prior setting of the userptr.

- Fix 64-bit problems in bsddb.

- Patch #1365916: fix some unsafe 64-bit mmap methods.

- Bug #1290333: Added a workaround for cjkcodecs' _codecs_cn build
  problem on AIX.

- Bug #869197: os.setgroups rejects long integer arguments

- Bug #1346533, select.poll() doesn't raise an error if timeout > sys.maxint

- Bug #1344508, Fix UNIX mmap leaking file descriptors

- Patch #1338314, Bug #1336623: fix tarfile so it can extract
  REGTYPE directories from tarfiles written by old programs.

- Patch #1407992, fixes broken bsddb module db associate when using
  BerkeleyDB 3.3, 4.0 or 4.1.

- Get bsddb module to build with BerkeleyDB version 4.4

- Get bsddb module to build with BerkeleyDB version 3.2

- Patch #1309009, Fix segfault in pyexpat when the XML document is in latin_1,
  but Python incorrectly assumes it is in UTF-8 format

- Fix parse errors in the readline module when compiling without threads.

- Patch #1288833: Removed thread lock from socket.getaddrinfo on
  FreeBSD 5.3 and later versions which got thread-safe getaddrinfo(3).

- Patches #1298449 and #1298499: Add some missing checks for error
  returns in cStringIO.c.

- Patch #1297028: fix segfault if call type on MultibyteCodec,
  MultibyteStreamReader, or MultibyteStreamWriter

- Fix memory leak in posix.access().

- Patch #1213831: Fix typo in unicodedata._getcode.

- Bug #1007046: os.startfile() did not accept unicode strings encoded in
  the file system encoding.

- Patch #756021: Special-case socket.inet_aton('255.255.255.255') for
  platforms that don't have inet_aton().

- Bug #1215928: Fix bz2.BZ2File.seek() for 64-bit file offsets.

- Bug #1191043: Fix bz2.BZ2File.(x)readlines for files containing one
  line without newlines.

- Bug #728515: mmap.resize() now resizes the file on Unix as it did
  on Windows.

- Patch #1180695: Add nanosecond stat resolution, and st_gen,
  st_birthtime for FreeBSD.

- Patch #1231069: The fcntl.ioctl function now uses the 'I' code for
  the request code argument, which results in more C-like behaviour
  for large or negative values.

- Bug #1234979: For the argument of thread.Lock.acquire, the Windows
  implementation treated all integer values except 1 as false.

- Bug #1194181: bz2.BZ2File didn't handle mode 'U' correctly.

- Patch #1212117: os.stat().st_flags is now accessible as a attribute
  if available on the platform.

- Patch #1103951: Expose O_SHLOCK and O_EXLOCK in the posix module if
  available on the platform.

- Bug #1166660: The readline module could segfault if hook functions
  were set in a different thread than that which called readline.

- collections.deque objects now support a remove() method.

- operator.itemgetter() and operator.attrgetter() now support retrieving
  multiple fields.  This provides direct support for sorting on multiple
  keys (primary, secondary, etc).

- os.access now supports Unicode path names on non-Win32 systems.

- Patches #925152, #1118602: Avoid reading after the end of the buffer
  in pyexpat.GetInputContext.

- Patches #749830, #1144555: allow UNIX mmap size to default to current
  file size.

- Added functional.partial().  See PEP309.

- Patch #1093585: raise a ValueError for negative history items in readline.
  {remove_history,replace_history}

- The spwd module has been added, allowing access to the shadow password
  database.

- stat_float_times is now True.

- array.array objects are now picklable.

- the cPickle module no longer accepts the deprecated None option in the
  args tuple returned by __reduce__().

- itertools.islice() now accepts None for the start and step arguments.
  This allows islice() to work more readily with slices:
      islice(s.start, s.stop, s.step)

- datetime.datetime() now has a strptime class method which can be used to
  create datetime object using a string and format.

- Patch #1117961: Replace the MD5 implementation from RSA Data Security Inc
  with the implementation from http://sourceforge.net/projects/libmd5-rfc/.

Library
-------

- Patch #1388073: Numerous __-prefixed attributes of unittest.TestCase have
  been renamed to have only a single underscore prefix.  This was done to
  make subclassing easier.

- PEP 338: new module runpy defines a run_module function to support
  executing modules which provide access to source code or a code object
  via the PEP 302 import mechanisms.

- The email module's parsedate_tz function now sets the daylight savings
  flag to -1 (unknown) since it can't tell from the date whether it should
  be set.

- Patch #624325: urlparse.urlparse() and urlparse.urlsplit() results
  now sport attributes that provide access to the parts of the result.

- Patch #1462498: sgmllib now handles entity and character references
  in attribute values.

- Added the sqlite3 package. This is based on pysqlite2.1.3, and provides
  a DB-API interface in the standard library. You'll need sqlite 3.0.8 or
  later to build this - if you have an earlier version, the C extension
  module will not be built.

- Bug #1460340: ``random.sample(dict)`` failed in various ways.  Dicts
  aren't officially supported here, and trying to use them will probably
  raise an exception some day.  But dicts have been allowed, and "mostly
  worked", so support for them won't go away without warning.

- Bug #1445068: getpass.getpass() can now be given an explicit stream
  argument to specify where to write the prompt.

- Patch #1462313, bug #1443328: the pickle modules now can handle classes
  that have __private names in their __slots__.

- Bug #1250170: mimetools now handles socket.gethostname() failures gracefully.

- patch #1457316: "setup.py upload" now supports --identity to select the
  key to be used for signing the uploaded code.

- Queue.Queue objects now support .task_done() and .join() methods
  to make it easier to monitor when daemon threads have completed
  processing all enqueued tasks.  Patch #1455676.

- popen2.Popen objects now preserve the command in a .cmd attribute.

- Added the ctypes ffi package.

- email 4.0 package now integrated.  This is largely the same as the email 3.0
  package that was included in Python 2.3, except that PEP 8 module names are
  now used (e.g. mail.message instead of email.Message).  The MIME classes
  have been moved to a subpackage (e.g. email.mime.text instead of
  email.MIMEText).  The old names are still supported for now.  Several
  deprecated Message methods have been removed and lots of bugs have been
  fixed.  More details can be found in the email package documentation.

- Patches #1436130/#1443155: codecs.lookup() now returns a CodecInfo object
  (a subclass of tuple) that provides incremental decoders and encoders
  (a way to use stateful codecs without the stream API). Python functions
  codecs.getincrementaldecoder() and codecs.getincrementalencoder() as well
  as C functions PyCodec_IncrementalEncoder() and PyCodec_IncrementalDecoder()
  have been added.

- Patch #1359365: Calling next() on a closed StringIO.String object raises
  a ValueError instead of a StopIteration now (like file and cString.String do).
  cStringIO.StringIO.isatty() will raise a ValueError now if close() has been
  called before (like file and StringIO.StringIO do).

- A regrtest option -w was added to re-run failed tests in verbose mode.

- Patch #1446372: quit and exit can now be called from the interactive
  interpreter to exit.

- The function get_count() has been added to the gc module, and gc.collect()
  grew an optional 'generation' argument.

- A library msilib to generate Windows Installer files, and a distutils
  command bdist_msi have been added.

- PEP 343: new module contextlib.py defines decorator @contextmanager
  and helpful context managers nested() and closing().

- The compiler package now supports future imports after the module docstring.

- Bug #1413790: zipfile now sanitizes absolute archive names that are
  not allowed by the specs.

- Patch #1215184: FileInput now can be given an opening hook which can
  be used to control how files are opened.

- Patch #1212287: fileinput.input() now has a mode parameter for
  specifying the file mode input files should be opened with.

- Patch #1215184: fileinput now has a fileno() function for getting the
  current file number.

- Patch #1349274: gettext.install() now optionally installs additional
  translation functions other than _() in the builtin namespace.

- Patch #1337756: fileinput now accepts Unicode filenames.

- Patch #1373643: The chunk module can now read chunks larger than
  two gigabytes.

- Patch #1417555: SimpleHTTPServer now returns Last-Modified headers.

- Bug #1430298: It is now possible to send a mail with an empty
  return address using smtplib.

- Bug #1432260: The names of lambda functions are now properly displayed
  in pydoc.

- Patch #1412872: zipfile now sets the creator system to 3 (Unix)
  unless the system is Win32.

- Patch #1349118: urllib now supports user:pass@ style proxy
  specifications, raises IOErrors when proxies for unsupported protocols
  are defined, and uses the https proxy on https redirections.

- Bug #902075: urllib2 now supports 'host:port' style proxy specifications.

- Bug #1407902: Add support for sftp:// URIs to urlparse.

- Bug #1371247: Update Windows locale identifiers in locale.py.

- Bug #1394565: SimpleHTTPServer now doesn't choke on query parameters
  any more.

- Bug #1403410: The warnings module now doesn't get confused
  when it can't find out the module name it generates a warning for.

- Patch #1177307: Added a new codec utf_8_sig for UTF-8 with a BOM signature.

- Patch #1157027: cookielib mishandles RFC 2109 cookies in Netscape mode

- Patch #1117398: cookielib.LWPCookieJar and .MozillaCookieJar now raise
  LoadError as documented, instead of IOError.  For compatibility,
  LoadError subclasses IOError.

- Added the hashlib module.  It provides secure hash functions for MD5 and
  SHA1, 224, 256, 384, and 512.  Note that recent developments make the
  historic MD5 and SHA1 unsuitable for cryptographic-strength applications.
  In <http://mail.python.org/pipermail/python-dev/2005-December/058850.html>
  Ronald L. Rivest offered this advice for Python:

      "The consensus of researchers in this area (at least as
      expressed at the NIST Hash Function Workshop 10/31/05),
      is that SHA-256 is a good choice for the time being, but
      that research should continue, and other alternatives may
      arise from this research.  The larger SHA's also seem OK."

- Added a subset of Fredrik Lundh's ElementTree package.  Available
  modules are xml.etree.ElementTree, xml.etree.ElementPath, and
  xml.etree.ElementInclude, from ElementTree 1.2.6.

- Patch #1162825: Support non-ASCII characters in IDLE window titles.

- Bug #1365984: urllib now opens "data:" URLs again.

- Patch #1314396: prevent deadlock for threading.Thread.join() when an exception
  is raised within the method itself on a previous call (e.g., passing in an
  illegal argument)

- Bug #1340337: change time.strptime() to always return ValueError when there
  is an error in the format string.

- Patch #754022: Greatly enhanced webbrowser.py (by Oleg Broytmann).

- Bug #729103: pydoc.py: Fix docother() method to accept additional
  "parent" argument.

- Patch #1300515: xdrlib.py: Fix pack_fstring() to really use null bytes
  for padding.

- Bug #1296004: httplib.py: Limit maximal amount of data read from the
  socket to avoid a MemoryError on Windows.

- Patch #1166948: locale.py: Prefer LC_ALL, LC_CTYPE and LANG over LANGUAGE
  to get the correct encoding.

- Patch #1166938: locale.py: Parse LANGUAGE as a colon separated list of
  languages.

- Patch #1268314: Cache lines in StreamReader.readlines for performance.

- Bug #1290505: Fix clearing the regex cache for time.strptime().

- Bug #1167128: Fix size of a symlink in a tarfile to be 0.

- Patch #810023: Fix off-by-one bug in urllib.urlretrieve reporthook
  functionality.

- Bug #1163178: Make IDNA return an empty string when the input is empty.

- Patch #848017: Make Cookie more RFC-compliant. Use CRLF as default output
  separator and do not output trailing semicolon.

- Patch #1062060: urllib.urlretrieve() now raises a new exception, named
  ContentTooShortException, when the actually downloaded size does not
  match the Content-Length header.

- Bug #1121494: distutils.dir_utils.mkpath now accepts Unicode strings.

- Bug #1178484: Return complete lines from codec stream readers
  even if there is an exception in later lines, resulting in
  correct line numbers for decoding errors in source code.

- Bug #1192315: Disallow negative arguments to clear() in pdb.

- Patch #827386: Support absolute source paths in msvccompiler.py.

- Patch #1105730: Apply the new implementation of commonprefix in posixpath
  to ntpath, macpath, os2emxpath and riscospath.

- Fix a problem in Tkinter introduced by SF patch #869468: delete bogus
  __hasattr__ and __delattr__ methods on class Tk that were breaking
  Tkdnd.

- Bug #1015140: disambiguated the term "article id" in nntplib docs and
  docstrings to either "article number" or "message id".

- Bug #1238170: threading.Thread.__init__ no longer has "kwargs={}" as a
  parameter, but uses the usual "kwargs=None".

- textwrap now processes text chunks at O(n) speed instead of O(n**2).
  Patch #1209527 (Contributed by Connelly).

- urllib2 has now an attribute 'httpresponses' mapping from HTTP status code
  to W3C name (404 -> 'Not Found'). RFE #1216944.

- Bug #1177468: Don't cache the /dev/urandom file descriptor for os.urandom,
  as this can cause problems with apps closing all file descriptors.

- Bug #839151: Fix an attempt to access sys.argv in the warnings module;
  it can be missing in embedded interpreters

- Bug #1155638: Fix a bug which affected HTTP 0.9 responses in httplib.

- Bug #1100201: Cross-site scripting was possible on BaseHTTPServer via
  error messages.

- Bug #1108948: Cookie.py produced invalid JavaScript code.

- The tokenize module now detects and reports indentation errors.
  Bug #1224621.

- The tokenize module has a new untokenize() function to support a full
  roundtrip from lexed tokens back to Python source code.  In addition,
  the generate_tokens() function now accepts a callable argument that
  terminates by raising StopIteration.

- Bug #1196315: fix weakref.WeakValueDictionary constructor.

- Bug #1213894: os.path.realpath didn't resolve symlinks that were the first
  component of the path.

- Patch #1120353: The xmlrpclib module provides better, more transparent,
  support for datetime.{datetime,date,time} objects.  With use_datetime set
  to True, applications shouldn't have to fiddle with the DateTime wrapper
  class at all.

- distutils.commands.upload was added to support uploading distribution
  files to PyPI.

- distutils.commands.register now encodes the data as UTF-8 before posting
  them to PyPI.

- decimal operator and comparison methods now return NotImplemented
  instead of raising a TypeError when interacting with other types.  This
  allows other classes to implement __radd__ style methods and have them
  work as expected.

- Bug #1163325:  Decimal infinities failed to hash.  Attempting to
  hash a NaN raised an InvalidOperation instead of a TypeError.

- Patch #918101: Add tarfile open mode r|* for auto-detection of the
  stream compression; add, for symmetry reasons, r:* as a synonym of r.

- Patch #1043890: Add extractall method to tarfile.

- Patch #1075887: Don't require MSVC in distutils if there is nothing
  to build.

- Patch #1103407: Properly deal with tarfile iterators when untarring
  symbolic links on Windows.

- Patch #645894: Use getrusage for computing the time consumption in
  profile.py if available.

- Patch #1046831: Use get_python_version where appropriate in sysconfig.py.

- Patch #1117454: Remove code to special-case cookies without values
  in LWPCookieJar.

- Patch #1117339: Add cookielib special name tests.

- Patch #1112812: Make bsddb/__init__.py more friendly for modulefinder.

- Patch #1110248: SYNC_FLUSH the zlib buffer for GZipFile.flush.

- Patch #1107973: Allow to iterate over the lines of a tarfile.ExFileObject.

- Patch #1104111: Alter setup.py --help and --help-commands.

- Patch #1121234: Properly cleanup _exit and tkerror commands.

- Patch #1049151: xdrlib now unpacks booleans as True or False.

- Fixed bug in a NameError bug in cookielib.  Patch #1116583.

- Applied a security fix to SimpleXMLRPCserver (PSF-2005-001).  This
  disables recursive traversal through instance attributes, which can
  be exploited in various ways.

- Bug #1222790: in SimpleXMLRPCServer, set the reuse-address and close-on-exec
  flags on the HTTP listening socket.

- Bug #792570: SimpleXMLRPCServer had problems if the request grew too large.
  Fixed by reading the HTTP body in chunks instead of one big socket.read().

- Patches #893642, #1039083: add allow_none, encoding arguments to constructors of
  SimpleXMLRPCServer and CGIXMLRPCRequestHandler.

- Bug #1110478: Revert os.environ.update to do putenv again.

- Bug #1103844: fix distutils.install.dump_dirs() with negated options.

- os.{SEEK_SET, SEEK_CUR, SEEK_END} have been added for convenience.

- Enhancements to the csv module:

  + Dialects are now validated by the underlying C code, better
    reflecting its capabilities, and improving its compliance with
    PEP 305.
  + Dialect parameter parsing has been re-implemented to improve error
    reporting.
  + quotechar=None and quoting=QUOTE_NONE now work the way PEP 305
    dictates.
  + the parser now removes the escapechar prefix from escaped characters.
  + when quoting=QUOTE_NONNUMERIC, the writer now tests for numeric
    types, rather than any object that can be represented as a numeric.
  + when quoting=QUOTE_NONNUMERIC, the reader now casts unquoted fields
    to floats.
  + reader now allows \r characters to be quoted (previously it only allowed
    \n to be quoted).
  + writer doublequote handling improved.
  + Dialect classes passed to the module are no longer instantiated by
    the module before being parsed (the former validation scheme required
    this, but the mechanism was unreliable).
  + The dialect registry now contains instances of the internal
    C-coded dialect type, rather than references to python objects.
  + the internal c-coded dialect type is now immutable.
  + register_dialect now accepts the same keyword dialect specifications
    as the reader and writer, allowing the user to register dialects
    without first creating a dialect class.
  + a configurable limit to the size of parsed fields has been added -
    previously, an unmatched quote character could result in the entire
    file being read into the field buffer before an error was reported.
  + A new module method csv.field_size_limit() has been added that sets
    the parser field size limit (returning the former limit). The initial
    limit is 128kB.
  + A line_num attribute has been added to the reader object, which tracks
    the number of lines read from the source iterator. This is not
    the same as the number of records returned, as records can span
    multiple lines.
  + reader and writer objects were not being registered with the cyclic-GC.
    This has been fixed.

- _DummyThread objects in the threading module now delete self.__block that is
  inherited from _Thread since it uses up a lock allocated by 'thread'.  The
  lock primitives tend to be limited in number and thus should not be wasted on
  a _DummyThread object.  Fixes bug #1089632.

- The imghdr module now detects Exif files.

- StringIO.truncate() now correctly adjusts the size attribute.
  (Bug #951915).

- locale.py now uses an updated locale alias table (built using
  Tools/i18n/makelocalealias.py, a tool to parse the X11 locale
  alias file); the encoding lookup was enhanced to use Python's
  encoding alias table.

- moved deprecated modules to Lib/lib-old:  whrandom, tzparse, statcache.

- the pickle module no longer accepts the deprecated None option in the
  args tuple returned by __reduce__().

- optparse now optionally imports gettext.  This allows its use in setup.py.

- the pickle module no longer uses the deprecated bin parameter.

- the shelve module no longer uses the deprecated binary parameter.

- the pstats module no longer uses the deprecated ignore() method.

- the filecmp module no longer uses the deprecated use_statcache argument.

- unittest.TestCase.run() and unittest.TestSuite.run() can now be successfully
  extended or overridden by subclasses.  Formerly, the subclassed method would
  be ignored by the rest of the module.  (Bug #1078905).

- heapq.nsmallest() and heapq.nlargest() now support key= arguments with
  the same meaning as in list.sort().

- Bug #1076985: ``codecs.StreamReader.readline()`` now calls ``read()`` only
  once when a size argument is given. This prevents a buffer overflow in the
  tokenizer with very long source lines.

- Bug #1083110: ``zlib.decompress.flush()`` would segfault if called
  immediately after creating the object, without any intervening
  ``.decompress()`` calls.

- The reconvert.quote function can now emit triple-quoted strings.  The
  reconvert module now has some simple documentation.

- ``UserString.MutableString`` now supports negative indices in
  ``__setitem__`` and ``__delitem__``

- Bug #1149508: ``textwrap`` now handles hyphenated numbers (eg. "2004-03-05")
  correctly.

- Partial fixes for SF bugs #1163244 and #1175396: If a chunk read by
  ``codecs.StreamReader.readline()`` has a trailing "\r", read one more
  character even if the user has passed a size parameter to get a proper
  line ending. Remove the special handling of a "\r\n" that has been split
  between two lines.

- Bug #1251300: On UCS-4 builds the "unicode-internal" codec will now complain
  about illegal code points. The codec now supports PEP 293 style error
  handlers.

- Bug #1235646: ``codecs.StreamRecoder.next()`` now reencodes the data it reads
  from the input stream, so that the output is a byte string in the correct
  encoding instead of a unicode string.

- Bug #1202493: Fixing SRE parser to handle '{}' as perl does, rather than
  considering it exactly like a '*'.

- Bug #1245379: Add "unicode-1-1-utf-7" as an alias for "utf-7" to
  ``encodings.aliases``.

- ` uu.encode()`` and ``uu.decode()`` now support unicode filenames.

- Patch #1413711: Certain patterns of differences were making difflib
  touch the recursion limit.

- Bug #947906: An object oriented interface has been added to the calendar
  module. It's possible to generate HTML calendar now and the module can be
  called as a script (e.g. via ``python -mcalendar``). Localized month and
  weekday names can be ouput (even if an exotic encoding is used) using
  special classes that use unicode.

Build
-----

- Fix test_float, test_long, and test_struct failures on Tru64 with gcc
  by using -mieee gcc option.

- Patch #1432345: Make python compile on DragonFly.

- Build support for Win64-AMD64 was added.

- Patch #1428494: Prefer linking against ncursesw over ncurses library.

- Patch #881820: look for openpty and forkpty also in libbsd.

- The sources of zlib are now part of the Python distribution (zlib 1.2.3).
  The zlib module is now builtin on Windows.

- Use -xcode=pic32 for CCSHARED on Solaris with SunPro.

- Bug #1189330: configure did not correctly determine the necessary
  value of LINKCC if python was built with GCC 4.0.

- Upgrade Windows build to zlib 1.2.3 which eliminates a potential security
  vulnerability in zlib 1.2.1 and 1.2.2.

- EXTRA_CFLAGS has been introduced as an environment variable to hold compiler
  flags that change binary compatibility.  Changes were also made to
  distutils.sysconfig to also use the environment variable when used during
  compilation of the interpreter and of C extensions through distutils.

- SF patch 1171735: Darwin 8's headers are anal about POSIX compliance,
  and linking has changed (prebinding is now deprecated, and libcc_dynamic
  no longer exists). This configure patch makes things right.

- Bug #1158607: Build with --disable-unicode again.

- spwdmodule.c is built only if either HAVE_GETSPNAM or HAVE_HAVE_GETSPENT is
  defined.  Discovered as a result of not being able to build on OS X.

- setup.py now uses the directories specified in LDFLAGS using the -L option
  and in CPPFLAGS using the -I option for adding library and include
  directories, respectively, for compiling extension modules against.  This has
  led to the core being compiled using the values in CPPFLAGS.  It also removes
  the need for the special-casing of both DarwinPorts and Fink for darwin since
  the proper directories can be specified in LDFLAGS (``-L/sw/lib`` for Fink,
  ``-L/opt/local/lib`` for DarwinPorts) and CPPFLAGS (``-I/sw/include`` for
  Fink, ``-I/opt/local/include`` for DarwinPorts).

- Test in configure.in that checks for tzset no longer dependent on tm->tm_zone
  to exist in the struct (not required by either ISO C nor the UNIX 2 spec).
  Tests for sanity in tzname when HAVE_TZNAME defined were also defined.
  Closes bug #1096244.  Thanks Gregory Bond.

C API
-----

- ``PyMem_{Del, DEL}`` and ``PyMem_{Free, FREE}`` no longer map to
  ``PyObject_{Free, FREE}``.  They map to the system ``free()`` now.  If memory
  is obtained via the ``PyObject_`` family, it must be released via the
  ``PyObject_`` family, and likewise for the ``PyMem_`` family.  This has
  always been officially true, but when Python's small-object allocator was
  introduced, an attempt was made to cater to a few extension modules
  discovered at the time that obtained memory via ``PyObject_New`` but
  released it via ``PyMem_DEL``.  It's years later, and if such code still
  exists it will fail now (probably with segfaults, but calling wrong
  low-level memory management functions can yield many symptoms).

- Added a C API for set and frozenset objects.

- Removed PyRange_New().

- Patch #1313939: PyUnicode_DecodeCharmap() accepts a unicode string as the
  mapping argument now. This string is used as a mapping table. Byte values
  greater than the length of the string and 0xFFFE are treated as undefined
  mappings.


Tests
-----

- In test_os, st_?time is now truncated before comparing it with ST_?TIME.

- Patch #1276356: New resource "urlfetch" is implemented.  This enables
  even impatient people to run tests that require remote files.


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

- Bug #1402224: Add warning to dl docs about crashes.

- Bug #1396471: Document that Windows' ftell() can return invalid
  values for text files with UNIX-style line endings.

- Bug #1274828: Document os.path.splitunc().

- Bug #1190204: Clarify which directories are searched by site.py.

- Bug #1193849: Clarify os.path.expanduser() documentation.

- Bug #1243192: re.UNICODE and re.LOCALE affect \d, \D, \s and \S.

- Bug #755617: Document the effects of os.chown() on Windows.

- Patch #1180012: The documentation for modulefinder is now in the library reference.

- Patch #1213031: Document that os.chown() accepts argument values of -1.

- Bug #1190563: Document os.waitpid() return value with WNOHANG flag.

- Bug #1175022: Correct the example code for property().

- Document the IterableUserDict class in the UserDict module.
  Closes bug #1166582.

- Remove all latent references for "Macintosh" that referred to semantics for
  Mac OS 9 and change to reflect the state for OS X.
  Closes patch #1095802.  Thanks Jack Jansen.

Mac
---


New platforms
-------------

- FreeBSD 7 support is added.


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

- Created Misc/Vim/vim_syntax.py to auto-generate a python.vim file in that
  directory for syntax highlighting in Vim.  Vim directory was added and placed
  vimrc to it (was previous up a level).

- Added two new files to Tools/scripts: pysource.py, which recursively
  finds Python source files, and findnocoding.py, which finds Python
  source files that need an encoding declaration.
  Patch #784089, credits to Oleg Broytmann.

- Bug #1072853: pindent.py used an uninitialized variable.

- Patch #1177597: Correct Complex.__init__.

- Fixed a display glitch in Pynche, which could cause the right arrow to
  wiggle over by a pixel.

----

**(For information about older versions, consult the HISTORY file.)**