| What's New in Python 2.2a0? |
| =========================== |
| |
| Core |
| |
| - Dictionary objects now support the "in" operator: "x in dict" means |
| the same as dict.has_key(x). |
| |
| - Iterators were added; this is a generalized way of providing values |
| to a for loop. See PEP 234. There's a new built-in function iter() |
| to return an iterator. There's a new protocol to get the next value |
| from an iterator using the next() method (in Python) or the |
| tp_iternext slot (in C). There's a new protocol to get iterators |
| using the __iter__() method (in Python) or the tp_iter slot (in C). |
| Iterating (i.e. a for loop) over a dictionary generates its keys. |
| Iterating over a file generates its lines. |
| |
| - The following functions were generalized to work nicely with iterator |
| arguments: |
| filter() |
| list() |
| map() |
| max() |
| min() |
| reduce() |
| XXX TODO string.join(), unicode.join() |
| XXX TODO tuple() |
| XXX TODO zip() |
| |
| What's New in Python 2.1 (final)? |
| ================================= |
| |
| We only changed a few things since the last release candidate, all in |
| Python library code: |
| |
| - A bug in the locale module was fixed that affected locales which |
| define no grouping for numeric formatting. |
| |
| - A few bugs in the weakref module's implementations of weak |
| dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed, |
| and the test suite was updated to check for these bugs. |
| |
| - An old bug in the os.path.walk() function (introduced in Python |
| 2.0!) was fixed: a non-existent file would cause an exception |
| instead of being ignored. |
| |
| - Fixed a few bugs in the new symtable module found by Neil Norwitz's |
| PyChecker. |
| |
| |
| What's New in Python 2.1c2? |
| =========================== |
| |
| A flurry of small changes, and one showstopper fixed in the nick of |
| time made it necessary to release another release candidate. The list |
| here is the *complete* list of patches (except version updates): |
| |
| Core |
| |
| - Tim discovered a nasty bug in the dictionary code, caused by |
| PyDict_Next() calling dict_resize(), and the GC code's use of |
| PyDict_Next() violating an assumption in dict_items(). This was |
| fixed with considerable amounts of band-aid, but the net effect is a |
| saner and more robust implementation. |
| |
| - Made a bunch of symbols static that were accidentally global. |
| |
| Build and Ports |
| |
| - The setup.py script didn't check for a new enough version of zlib |
| (1.1.3 is needed). Now it does. |
| |
| - Changed "make clean" target to also remove shared libraries. |
| |
| - Added a more general warning about the SGI Irix optimizer to README. |
| |
| Library |
| |
| - Fix a bug in urllib.basejoin("http://host", "../file.html") which |
| omitted the slash between host and file.html. |
| |
| - The mailbox module's _Mailbox class contained a completely broken |
| and undocumented seek() method. Ripped it out. |
| |
| - Fixed a bunch of typos in various library modules (urllib2, smtpd, |
| sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker. |
| |
| - Fixed a few last-minute bugs in unittest. |
| |
| Extensions |
| |
| - Reverted the patch to the OpenSSL code in socketmodule.c to support |
| RAND_status() and the EGD, and the subsequent patch that tried to |
| fix it for pre-0.9.5 versions; the problem with the patch is that on |
| some systems it issues a warning whenever socket is imported, and |
| that's unacceptable. |
| |
| Tests |
| |
| - Fixed the pickle tests to work with "import test.test_pickle". |
| |
| - Tweaked test_locale.py to actually run the test Windows. |
| |
| - In distutils/archive_util.py, call zipfile.ZipFile() with mode "w", |
| not "wb" (which is not a valid mode at all). |
| |
| - Fix pstats browser crashes. Import readline if it exists to make |
| the user interface nicer. |
| |
| - Add "import thread" to the top of test modules that import the |
| threading module (test_asynchat and test_threadedtempfile). This |
| prevents test failures caused by a broken threading module resulting |
| from a previously caught failed import. |
| |
| - Changed test_asynchat.py to set the SO_REUSEADDR option; this was |
| needed on some platforms (e.g. Solaris 8) when the tests are run |
| twice in succession. |
| |
| - Skip rather than fail test_sunaudiodev if no audio device is found. |
| |
| |
| What's New in Python 2.1c1? |
| =========================== |
| |
| This list was significantly updated when 2.1c2 was released; the 2.1c1 |
| release didn't mention most changes that were actually part of 2.1c1: |
| |
| Legal |
| |
| - Copyright was assigned to the Python Software Foundation (PSF) and a |
| PSF license (very similar to the CNRI license) was added. |
| |
| - The CNRI copyright notice was updated to include 2001. |
| |
| Core |
| |
| - After a public outcry, assignment to __debug__ is no longer illegal; |
| instead, a warning is issued. It will become illegal in 2.2. |
| |
| - Fixed a core dump with "%#x" % 0, and changed the semantics so that |
| "%#x" now always prepends "0x", even if the value is zero. |
| |
| - Fixed some nits in the bytecode compiler. |
| |
| - Fixed core dumps when calling certain kinds of non-functions. |
| |
| - Fixed various core dumps caused by reference count bugs. |
| |
| Build and Ports |
| |
| - Use INSTALL_SCRIPT to install script files. |
| |
| - New port: SCO Unixware 7, by Billy G. Allie. |
| |
| - Updated RISCOS port. |
| |
| - Updated BeOS port and notes. |
| |
| - Various other porting problems resolved. |
| |
| Library |
| |
| - The TERMIOS and SOCKET modules are now truly obsolete and |
| unnecessary. Their symbols are incorporated in the termios and |
| socket modules. |
| |
| - Fixed some 64-bit bugs in pickle, cPickle, and struct, and added |
| better tests for pickling. |
| |
| - threading: make Condition.wait() robust against KeyboardInterrupt. |
| |
| - zipfile: add support to zipfile to support opening an archive |
| represented by an open file rather than a file name. Fix bug where |
| the archive was not properly closed. Fixed a bug in this bugfix |
| where flush() was called for a read-only file. |
| |
| - imputil: added an uninstall() method to the ImportManager. |
| |
| - Canvas: fixed bugs in lower() and tkraise() methods. |
| |
| - SocketServer: API change (added overridable close_request() method) |
| so that the TCP server can explicitly close the request. |
| |
| - pstats: Eric Raymond added a simple interactive statistics browser, |
| invoked when the module is run as a script. |
| |
| - locale: fixed a problem in format(). |
| |
| - webbrowser: made it work when the BROWSER environment variable has a |
| value like "/usr/bin/netscape". Made it auto-detect Konqueror for |
| KDE 2. Fixed some other nits. |
| |
| - unittest: changes to allow using a different exception than |
| AssertionError, and added a few more function aliases. Some other |
| small changes. |
| |
| - urllib, urllib2: fixed redirect problems and a coupleof other nits. |
| |
| - asynchat: fixed a critical bug in asynchat that slipped through the |
| 2.1b2 release. Fixed another rare bug. |
| |
| - Fix some unqualified except: clauses (always a bad code example). |
| |
| XML |
| |
| - pyexpat: new API get_version_string(). |
| |
| - Fixed some minidom bugs. |
| |
| Extensions |
| |
| - Fixed a core dump in _weakref. Removed the weakref.mapping() |
| function (it adds nothing to the API). |
| |
| - Rationalized the use of header files in the readline module, to make |
| it compile (albeit with some warnings) with the very recent readline |
| 4.2, without breaking for earlier versions. |
| |
| - Hopefully fixed a buffering problem in linuxaudiodev. |
| |
| - Attempted a fix to make the OpenSSL support in the socket module |
| work again with pre-0.9.5 versions of OpenSSL. |
| |
| Tests |
| |
| - Added a test case for asynchat and asyncore. |
| |
| - Removed coupling between tests where one test failing could break |
| another. |
| |
| Tools |
| |
| - Ping added an interactive help browser to pydoc, fixed some nits |
| in the rest of the pydoc code, and added some features to his |
| inspect module. |
| |
| - An updated python-mode.el version 4.1 which integrates Ken |
| Manheimer's pdbtrack.el. This makes debugging Python code via pdb |
| much nicer in XEmacs and Emacs. When stepping through your program |
| with pdb, in either the shell window or the *Python* window, the |
| source file and line will be tracked by an arrow. Very cool! |
| |
| - IDLE: syntax warnings in interactive mode are changed into errors. |
| |
| - Some improvements to Tools/webchecker (ignore some more URL types, |
| follow some more links). |
| |
| - Brought the Tools/compiler package up to date. |
| |
| |
| What's New in Python 2.1 beta 2? |
| ================================ |
| |
| (Unlisted are many fixed bugs, more documentation, etc.) |
| |
| Core language, builtins, and interpreter |
| |
| - The nested scopes work (enabled by "from __future__ import |
| nested_scopes") is completed; in particular, the future now extends |
| into code executed through exec, eval() and execfile(), and into the |
| interactive interpreter. |
| |
| - When calling a base class method (e.g. BaseClass.__init__(self)), |
| this is now allowed even if self is not strictly spoken a class |
| instance (e.g. when using metaclasses or the Don Beaudry hook). |
| |
| - Slice objects are now comparable but not hashable; this prevents |
| dict[:] from being accepted but meaningless. |
| |
| - Complex division is now calculated using less braindead algorithms. |
| This doesn't change semantics except it's more likely to give useful |
| results in extreme cases. Complex repr() now uses full precision |
| like float repr(). |
| |
| - sgmllib.py now calls handle_decl() for simple <!...> declarations. |
| |
| - It is illegal to assign to the name __debug__, which is set when the |
| interpreter starts. It is effectively a compile-time constant. |
| |
| - A warning will be issued if a global statement for a variable |
| follows a use or assignment of that variable. |
| |
| Standard library |
| |
| - unittest.py, a unit testing framework by Steve Purcell (PyUNIT, |
| inspired by JUnit), is now part of the standard library. You now |
| have a choice of two testing frameworks: unittest requires you to |
| write testcases as separate code, doctest gathers them from |
| docstrings. Both approaches have their advantages and |
| disadvantages. |
| |
| - A new module Tix was added, which wraps the Tix extension library |
| for Tk. With that module, it is not necessary to statically link |
| Tix with _tkinter, since Tix will be loaded with Tcl's "package |
| require" command. See Demo/tix/. |
| |
| - tzparse.py is now obsolete. |
| |
| - In gzip.py, the seek() and tell() methods are removed -- they were |
| non-functional anyway, and it's better if callers can test for their |
| existence with hasattr(). |
| |
| Python/C API |
| |
| - PyDict_Next(): it is now safe to call PyDict_SetItem() with a key |
| that's already in the dictionary during a PyDict_Next() iteration. |
| This used to fail occasionally when a dictionary resize operation |
| could be triggered that would rehash all the keys. All other |
| modifications to the dictionary are still off-limits during a |
| PyDict_Next() iteration! |
| |
| - New extended APIs related to passing compiler variables around. |
| |
| - New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass() |
| implement isinstance() and issubclass(). |
| |
| - Py_BuildValue() now has a "D" conversion to create a Python complex |
| number from a Py_complex C value. |
| |
| - Extensions types which support weak references must now set the |
| field allocated for the weak reference machinery to NULL themselves; |
| this is done to avoid the cost of checking each object for having a |
| weakly referencable type in PyObject_INIT(), since most types are |
| not weakly referencable. |
| |
| - PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for |
| free variables and cell variables to and from the frame's f_locals. |
| |
| - Variants of several functions defined in pythonrun.h have been added |
| to support the nested_scopes future statement. The variants all end |
| in Flags and take an extra argument, a PyCompilerFlags *; examples: |
| PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These |
| variants may be removed in Python 2.2, when nested scopes are |
| mandatory. |
| |
| Distutils |
| |
| - the sdist command now writes a PKG-INFO file, as described in PEP 241, |
| into the release tree. |
| |
| - several enhancements to the bdist_wininst command from Thomas Heller |
| (an uninstaller, more customization of the installer's display) |
| |
| - from Jack Jansen: added Mac-specific code to generate a dialog for |
| users to specify the command-line (because providing a command-line with |
| MacPython is awkward). Jack also made various fixes for the Mac |
| and the Metrowerks compiler. |
| |
| - added 'platforms' and 'keywords' to the set of metadata that can be |
| specified for a distribution. |
| |
| - applied patches from Jason Tishler to make the compiler class work with |
| Cygwin. |
| |
| |
| What's New in Python 2.1 beta 1? |
| ================================ |
| |
| Core language, builtins, and interpreter |
| |
| - Following an outcry from the community about the amount of code |
| broken by the nested scopes feature introduced in 2.1a2, we decided |
| to make this feature optional, and to wait until Python 2.2 (or at |
| least 6 months) to make it standard. The option can be enabled on a |
| per-module basis by adding "from __future__ import nested_scopes" at |
| the beginning of a module (before any other statements, but after |
| comments and an optional docstring). See PEP 236 (Back to the |
| __future__) for a description of the __future__ statement. PEP 227 |
| (Statically Nested Scopes) has been updated to reflect this change, |
| and to clarify the semantics in a number of endcases. |
| |
| - The nested scopes code, when enabled, has been hardened, and most |
| bugs and memory leaks in it have been fixed. |
| |
| - Compile-time warnings are now generated for a number of conditions |
| that will break or change in meaning when nested scopes are enabled: |
| |
| - Using "from...import *" or "exec" without in-clause in a function |
| scope that also defines a lambda or nested function with one or |
| more free (non-local) variables. The presence of the import* or |
| bare exec makes it impossible for the compiler to determine the |
| exact set of local variables in the outer scope, which makes it |
| impossible to determine the bindings for free variables in the |
| inner scope. To avoid the warning about import *, change it into |
| an import of explicitly name object, or move the import* statement |
| to the global scope; to avoid the warning about bare exec, use |
| exec...in... (a good idea anyway -- there's a possibility that |
| bare exec will be deprecated in the future). |
| |
| - Use of a global variable in a nested scope with the same name as a |
| local variable in a surrounding scope. This will change in |
| meaning with nested scopes: the name in the inner scope will |
| reference the variable in the outer scope rather than the global |
| of the same name. To avoid the warning, either rename the outer |
| variable, or use a global statement in the inner function. |
| |
| - An optional object allocator has been included. This allocator is |
| optimized for Python objects and should be faster and use less memory |
| than the standard system allocator. It is not enabled by default |
| because of possible thread safety problems. The allocator is only |
| protected by the Python interpreter lock and it is possible that some |
| extension modules require a thread safe allocator. The object |
| allocator can be enabled by providing the "--with-pymalloc" option to |
| configure. |
| |
| Standard library |
| |
| - pyexpat now detects the expat version if expat.h defines it. A |
| number of additional handlers are provided, which are only available |
| since expat 1.95. In addition, the methods SetParamEntityParsing and |
| GetInputContext of Parser objects are available with 1.95.x |
| only. Parser objects now provide the ordered_attributes and |
| specified_attributes attributes. A new module expat.model was added, |
| which offers a number of additional constants if 1.95.x is used. |
| |
| - xml.dom offers the new functions registerDOMImplementation and |
| getDOMImplementation. |
| |
| - xml.dom.minidom offers a toprettyxml method. A number of DOM |
| conformance issues have been resolved. In particular, Element now |
| has an hasAttributes method, and the handling of namespaces was |
| improved. |
| |
| - Ka-Ping Yee contributed two new modules: inspect.py, a module for |
| getting information about live Python code, and pydoc.py, a module |
| for interactively converting docstrings to HTML or text. |
| Tools/scripts/pydoc, which is now automatically installed into |
| <prefix>/bin, uses pydoc.py to display documentation; try running |
| "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that |
| lets you browse the module docstrings using a web browser. |
| |
| - New library module difflib.py, primarily packaging the SequenceMatcher |
| class at the heart of the popular ndiff.py file-comparison tool. |
| |
| - doctest.py (a framework for verifying Python code examples in docstrings) |
| is now part of the std library. |
| |
| Windows changes |
| |
| - A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a |
| small GUI that lets you browse the module docstrings using your |
| default web browser. |
| |
| - Import is now case-sensitive. PEP 235 (Import on Case-Insensitive |
| Platforms) is implemented. See |
| |
| http://python.sourceforge.net/peps/pep-0235.html |
| |
| for full details, especially the "Current Lower-Left Semantics" section. |
| The new Windows import rules are simpler than before: |
| |
| A. If the PYTHONCASEOK environment variable exists, same as |
| before: silently accept the first case-insensitive match of any |
| kind; raise ImportError if none found. |
| |
| B. Else search sys.path for the first case-sensitive match; raise |
| ImportError if none found. |
| |
| The same rules have been implented on other platforms with case- |
| insensitive but case-preserving filesystems too (including Cygwin, and |
| several flavors of Macintosh operating systems). |
| |
| - winsound module: Under Win9x, winsound.Beep() now attempts to simulate |
| what it's supposed to do (and does do under NT and 2000) via direct |
| port manipulation. It's unknown whether this will work on all systems, |
| but it does work on my Win98SE systems now and was known to be useless on |
| all Win9x systems before. |
| |
| - Build: Subproject _test (effectively) renamed to _testcapi. |
| |
| New platforms |
| |
| - 2.1 should compile and run out of the box under MacOS X, even using HFS+. |
| Thanks to Steven Majewski! |
| |
| - 2.1 should compile and run out of the box on Cygwin. Thanks to Jason |
| Tishler! |
| |
| - 2.1 contains new files and patches for RISCOS, thanks to Dietmar |
| Schwertberger! See RISCOS/README for more information -- it seems |
| that because of the bizarre filename conventions on RISCOS, no port |
| to that platform is easy. Note that the new variable os.endsep is |
| silently supported in order to make life easier on this platform, |
| but we don't advertise it because it's not worth for most folks to |
| care about RISCOS portability. |
| |
| |
| What's New in Python 2.1 alpha 2? |
| ================================= |
| |
| Core language, builtins, and interpreter |
| |
| - Scopes nest. If a name is used in a function or class, but is not |
| local, the definition in the nearest enclosing function scope will |
| be used. One consequence of this change is that lambda statements |
| could reference variables in the namespaces where the lambda is |
| defined. In some unusual cases, this change will break code. |
| |
| In all previous version of Python, names were resolved in exactly |
| three namespaces -- the local namespace, the global namespace, and |
| the builtin namespace. According to this old definition, if a |
| function A is defined within a function B, the names bound in B are |
| not visible in A. The new rules make names bound in B visible in A, |
| unless A contains a name binding that hides the binding in B. |
| |
| Section 4.1 of the reference manual describes the new scoping rules |
| in detail. The test script in Lib/test/test_scope.py demonstrates |
| some of the effects of the change. |
| |
| The new rules will cause existing code to break if it defines nested |
| functions where an outer function has local variables with the same |
| name as globals or builtins used by the inner function. Example: |
| |
| def munge(str): |
| def helper(x): |
| return str(x) |
| if type(str) != type(''): |
| str = helper(str) |
| return str.strip() |
| |
| Under the old rules, the name str in helper() is bound to the |
| builtin function str(). Under the new rules, it will be bound to |
| the argument named str and an error will occur when helper() is |
| called. |
| |
| - The compiler will report a SyntaxError if "from ... import *" occurs |
| in a function or class scope. The language reference has documented |
| that this case is illegal, but the compiler never checked for it. |
| The recent introduction of nested scope makes the meaning of this |
| form of name binding ambiguous. In a future release, the compiler |
| may allow this form when there is no possibility of ambiguity. |
| |
| - repr(string) is easier to read, now using hex escapes instead of octal, |
| and using \t, \n and \r instead of \011, \012 and \015 (respectively): |
| |
| >>> "\texample \r\n" + chr(0) + chr(255) |
| '\texample \r\n\x00\xff' # in 2.1 |
| '\011example \015\012\000\377' # in 2.0 |
| |
| - Functions are now compared and hashed by identity, not by value, since |
| the func_code attribute is writable. |
| |
| - Weak references (PEP 205) have been added. This involves a few |
| changes in the core, an extension module (_weakref), and a Python |
| module (weakref). The weakref module is the public interface. It |
| includes support for "explicit" weak references, proxy objects, and |
| mappings with weakly held values. |
| |
| - A 'continue' statement can now appear in a try block within the body |
| of a loop. It is still not possible to use continue in a finally |
| clause. |
| |
| Standard library |
| |
| - mailbox.py now has a new class, PortableUnixMailbox which is |
| identical to UnixMailbox but uses a more portable scheme for |
| determining From_ separators. Also, the constructors for all the |
| classes in this module have a new optional `factory' argument, which |
| is a callable used when new message classes must be instantiated by |
| the next() method. |
| |
| - random.py is now self-contained, and offers all the functionality of |
| the now-deprecated whrandom.py. See the docs for details. random.py |
| also supports new functions getstate() and setstate(), for saving |
| and restoring the internal state of the generator; and jumpahead(n), |
| for quickly forcing the internal state to be the same as if n calls to |
| random() had been made. The latter is particularly useful for multi- |
| threaded programs, creating one instance of the random.Random() class for |
| each thread, then using .jumpahead() to force each instance to use a |
| non-overlapping segment of the full period. |
| |
| - random.py's seed() function is new. For bit-for-bit compatibility with |
| prior releases, use the whseed function instead. The new seed function |
| addresses two problems: (1) The old function couldn't produce more than |
| about 2**24 distinct internal states; the new one about 2**45 (the best |
| that can be done in the Wichmann-Hill generator). (2) The old function |
| sometimes produced identical internal states when passed distinct |
| integers, and there was no simple way to predict when that would happen; |
| the new one guarantees to produce distinct internal states for all |
| arguments in [0, 27814431486576L). |
| |
| - The socket module now supports raw packets on Linux. The socket |
| family is AF_PACKET. |
| |
| - test_capi.py is a start at running tests of the Python C API. The tests |
| are implemented by the new Modules/_testmodule.c. |
| |
| - A new extension module, _symtable, provides provisional access to the |
| internal symbol table used by the Python compiler. A higher-level |
| interface will be added on top of _symtable in a future release. |
| |
| - Removed the obsolete soundex module. |
| |
| - xml.dom.minidom now uses the standard DOM exceptions. Node supports |
| the isSameNode method; NamedNodeMap the get method. |
| |
| - xml.sax.expatreader supports the lexical handler property; it |
| generates comment, startCDATA, and endCDATA events. |
| |
| Windows changes |
| |
| - Build procedure: the zlib project is built in a different way that |
| ensures the zlib header files used can no longer get out of synch with |
| the zlib binary used. See PCbuild\readme.txt for details. Your old |
| zlib-related directories can be deleted; you'll need to download fresh |
| source for zlib and unpack it into a new directory. |
| |
| - Build: New subproject _test for the benefit of test_capi.py (see above). |
| |
| - Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent |
| interface to some Python compiler internals). |
| |
| - Build: Subproject ucnhash is gone, since the code was folded into the |
| unicodedata subproject. |
| |
| What's New in Python 2.1 alpha 1? |
| ================================= |
| |
| Core language, builtins, and interpreter |
| |
| - There is a new Unicode companion to the PyObject_Str() API |
| called PyObject_Unicode(). It behaves in the same way as the |
| former, but assures that the returned value is an Unicode object |
| (applying the usual coercion if necessary). |
| |
| - The comparison operators support "rich comparison overloading" (PEP |
| 207). C extension types can provide a rich comparison function in |
| the new tp_richcompare slot in the type object. The cmp() function |
| and the C function PyObject_Compare() first try the new rich |
| comparison operators before trying the old 3-way comparison. There |
| is also a new C API PyObject_RichCompare() (which also falls back on |
| the old 3-way comparison, but does not constrain the outcome of the |
| rich comparison to a Boolean result). |
| |
| The rich comparison function takes two objects (at least one of |
| which is guaranteed to have the type that provided the function) and |
| an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ, |
| Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python |
| object, which may be NotImplemented (in which case the tp_compare |
| slot function is used as a fallback, if defined). |
| |
| Classes can overload individual comparison operators by defining one |
| or more of the methods__lt__, __le__, __eq__, __ne__, __gt__, |
| __ge__. There are no explicit "reflected argument" versions of |
| these; instead, __lt__ and __gt__ are each other's reflection, |
| likewise for__le__ and __ge__; __eq__ and __ne__ are their own |
| reflection (similar at the C level). No other implications are |
| made; in particular, Python does not assume that == is the Boolean |
| inverse of !=, or that < is the Boolean inverse of >=. This makes |
| it possible to define types with partial orderings. |
| |
| Classes or types that want to implement (in)equality tests but not |
| the ordering operators (i.e. unordered types) should implement == |
| and !=, and raise an error for the ordering operators. |
| |
| It is possible to define types whose rich comparison results are not |
| Boolean; e.g. a matrix type might want to return a matrix of bits |
| for A < B, giving elementwise comparisons. Such types should ensure |
| that any interpretation of their value in a Boolean context raises |
| an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot |
| at the C level) to always raise an exception. |
| |
| - Complex numbers use rich comparisons to define == and != but raise |
| an exception for <, <=, > and >=. Unfortunately, this also means |
| that cmp() of two complex numbers raises an exception when the two |
| numbers differ. Since it is not mathematically meaningful to compare |
| complex numbers except for equality, I hope that this doesn't break |
| too much code. |
| |
| - The outcome of comparing non-numeric objects of different types is |
| not defined by the language, other than that it's arbitrary but |
| consistent (see the Reference Manual). An implementation detail changed |
| in 2.1a1 such that None now compares less than any other object. Code |
| relying on this new behavior (like code that relied on the previous |
| behavior) does so at its own risk. |
| |
| - Functions and methods now support getting and setting arbitrarily |
| named attributes (PEP 232). Functions have a new __dict__ |
| (a.k.a. func_dict) which hold the function attributes. Methods get |
| and set attributes on their underlying im_func. It is a TypeError |
| to set an attribute on a bound method. |
| |
| - The xrange() object implementation has been improved so that |
| xrange(sys.maxint) can be used on 64-bit platforms. There's still a |
| limitation that in this case len(xrange(sys.maxint)) can't be |
| calculated, but the common idiom "for i in xrange(sys.maxint)" will |
| work fine as long as the index i doesn't actually reach 2**31. |
| (Python uses regular ints for sequence and string indices; fixing |
| that is much more work.) |
| |
| - Two changes to from...import: |
| |
| 1) "from M import X" now works even if (after loading module M) |
| sys.modules['M'] is not a real module; it's basically a getattr() |
| operation with AttributeError exceptions changed into ImportError. |
| |
| 2) "from M import *" now looks for M.__all__ to decide which names to |
| import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but |
| filters out names starting with '_' as before. Whether or not |
| __all__ exists, there's no restriction on the type of M. |
| |
| - File objects have a new method, xreadlines(). This is the fastest |
| way to iterate over all lines in a file: |
| |
| for line in file.xreadlines(): |
| ...do something to line... |
| |
| See the xreadlines module (mentioned below) for how to do this for |
| other file-like objects. |
| |
| - Even if you don't use file.xreadlines(), you may expect a speedup on |
| line-by-line input. The file.readline() method has been optimized |
| quite a bit in platform-specific ways: on systems (like Linux) that |
| support flockfile(), getc_unlocked(), and funlockfile(), those are |
| used by default. On systems (like Windows) without getc_unlocked(), |
| a complicated (but still thread-safe) method using fgets() is used by |
| default. |
| |
| You can force use of the fgets() method by #define'ing |
| USE_FGETS_IN_GETLINE at build time (it may be faster than |
| getc_unlocked()). |
| |
| You can force fgets() not to be used by #define'ing |
| DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test |
| test_bufio.py fails -- and let us know if it does!). |
| |
| - In addition, the fileinput module, while still slower than the other |
| methods on most platforms, has been sped up too, by using |
| file.readlines(sizehint). |
| |
| - Support for run-time warnings has been added, including a new |
| command line option (-W) to specify the disposition of warnings. |
| See the description of the warnings module below. |
| |
| - Extensive changes have been made to the coercion code. This mostly |
| affects extension modules (which can now implement mixed-type |
| numerical operators without having to use coercion), but |
| occasionally, in boundary cases the coercion semantics have changed |
| subtly. Since this was a terrible gray area of the language, this |
| is considered an improvement. Also note that __rcmp__ is no longer |
| supported -- instead of calling __rcmp__, __cmp__ is called with |
| reflected arguments. |
| |
| - In connection with the coercion changes, a new built-in singleton |
| object, NotImplemented is defined. This can be returned for |
| operations that wish to indicate they are not implemented for a |
| particular combination of arguments. From C, this is |
| Py_NotImplemented. |
| |
| - The interpreter accepts now bytecode files on the command line even |
| if they do not have a .pyc or .pyo extension. On Linux, after executing |
| |
| import imp,sys,string |
| magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"") |
| reg = ':pyc:M::%s::%s:' % (magic, sys.executable) |
| open("/proc/sys/fs/binfmt_misc/register","wb").write(reg) |
| |
| any byte code file can be used as an executable (i.e. as an argument |
| to execve(2)). |
| |
| - %[xXo] formats of negative Python longs now produce a sign |
| character. In 1.6 and earlier, they never produced a sign, |
| and raised an error if the value of the long was too large |
| to fit in a Python int. In 2.0, they produced a sign if and |
| only if too large to fit in an int. This was inconsistent |
| across platforms (because the size of an int varies across |
| platforms), and inconsistent with hex() and oct(). Example: |
| |
| >>> "%x" % -0x42L |
| '-42' # in 2.1 |
| 'ffffffbe' # in 2.0 and before, on 32-bit machines |
| >>> hex(-0x42L) |
| '-0x42L' # in all versions of Python |
| |
| The behavior of %d formats for negative Python longs remains |
| the same as in 2.0 (although in 1.6 and before, they raised |
| an error if the long didn't fit in a Python int). |
| |
| %u formats don't make sense for Python longs, but are allowed |
| and treated the same as %d in 2.1. In 2.0, a negative long |
| formatted via %u produced a sign if and only if too large to |
| fit in an int. In 1.6 and earlier, a negative long formatted |
| via %u raised an error if it was too big to fit in an int. |
| |
| - Dictionary objects have an odd new method, popitem(). This removes |
| an arbitrary item from the dictionary and returns it (in the form of |
| a (key, value) pair). This can be useful for algorithms that use a |
| dictionary as a bag of "to do" items and repeatedly need to pick one |
| item. Such algorithms normally end up running in quadratic time; |
| using popitem() they can usually be made to run in linear time. |
| |
| Standard library |
| |
| - In the time module, the time argument to the functions strftime, |
| localtime, gmtime, asctime and ctime is now optional, defaulting to |
| the current time (in the local timezone). |
| |
| - The ftplib module now defaults to passive mode, which is deemed a |
| more useful default given that clients are often inside firewalls |
| these days. Note that this could break if ftplib is used to connect |
| to a *server* that is inside a firewall, from outside; this is |
| expected to be a very rare situation. To fix that, you can call |
| ftp.set_pasv(0). |
| |
| - The module site now treats .pth files not only for path configuration, |
| but also supports extensions to the initialization code: Lines starting |
| with import are executed. |
| |
| - There's a new module, warnings, which implements a mechanism for |
| issuing and filtering warnings. There are some new built-in |
| exceptions that serve as warning categories, and a new command line |
| option, -W, to control warnings (e.g. -Wi ignores all warnings, -We |
| turns warnings into errors). warnings.warn(message[, category]) |
| issues a warning message; this can also be called from C as |
| PyErr_Warn(category, message). |
| |
| - A new module xreadlines was added. This exports a single factory |
| function, xreadlines(). The intention is that this code is the |
| absolutely fastest way to iterate over all lines in an open |
| file(-like) object: |
| |
| import xreadlines |
| for line in xreadlines.xreadlines(file): |
| ...do something to line... |
| |
| This is equivalent to the previous the speed record holder using |
| file.readlines(sizehint). Note that if file is a real file object |
| (as opposed to a file-like object), this is equivalent: |
| |
| for line in file.xreadlines(): |
| ...do something to line... |
| |
| - The bisect module has new functions bisect_left, insort_left, |
| bisect_right and insort_right. The old names bisect and insort |
| are now aliases for bisect_right and insort_right. XXX_right |
| and XXX_left methods differ in what happens when the new element |
| compares equal to one or more elements already in the list: the |
| XXX_left methods insert to the left, the XXX_right methods to the |
| right. Code that doesn't care where equal elements end up should |
| continue to use the old, short names ("bisect" and "insort"). |
| |
| - The new curses.panel module wraps the panel library that forms part |
| of SYSV curses and ncurses. Contributed by Thomas Gellekum. |
| |
| - The SocketServer module now sets the allow_reuse_address flag by |
| default in the TCPServer class. |
| |
| - A new function, sys._getframe(), returns the stack frame pointer of |
| the caller. This is intended only as a building block for |
| higher-level mechanisms such as string interpolation. |
| |
| - The pyexpat module supports a number of new handlers, which are |
| available only in expat 1.2. If invocation of a callback fails, it |
| will report an additional frame in the traceback. Parser objects |
| participate now in garbage collection. If expat reports an unknown |
| encoding, pyexpat will try to use a Python codec; that works only |
| for single-byte charsets. The parser type objects is exposed as |
| XMLParserObject. |
| |
| - xml.dom now offers standard definitions for symbolic node type and |
| exception code constants, and a hierarchy of DOM exceptions. minidom |
| was adjusted to use them. |
| |
| - The conformance of xml.dom.minidom to the DOM specification was |
| improved. It detects a number of additional error cases; the |
| previous/next relationship works even when the tree is modified; |
| Node supports the normalize() method; NamedNodeMap, DocumentType and |
| DOMImplementation classes were added; Element supports the |
| hasAttribute and hasAttributeNS methods; and Text supports the splitText |
| method. |
| |
| Build issues |
| |
| - For Unix (and Unix-compatible) builds, configuration and building of |
| extension modules is now greatly automated. Rather than having to |
| edit the Modules/Setup file to indicate which modules should be |
| built and where their include files and libraries are, a |
| distutils-based setup.py script now takes care of building most |
| extension modules. All extension modules built this way are built |
| as shared libraries. Only a few modules that must be linked |
| statically are still listed in the Setup file; you won't need to |
| edit their configuration. |
| |
| - Python should now build out of the box on Cygwin. If it doesn't, |
| mail to Jason Tishler (jlt63 at users.sourceforge.net). |
| |
| - Python now always uses its own (renamed) implementation of getopt() |
| -- there's too much variation among C library getopt() |
| implementations. |
| |
| - C++ compilers are better supported; the CXX macro is always set to a |
| C++ compiler if one is found. |
| |
| Windows changes |
| |
| - select module: By default under Windows, a select() call |
| can specify no more than 64 sockets. Python now boosts |
| this Microsoft default to 512. If you need even more than |
| that, see the MS docs (you'll need to #define FD_SETSIZE |
| and recompile Python from source). |
| |
| - Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3 |
| subdirectory is no more! |
| |
| |
| What's New in Python 2.0? |
| ========================= |
| |
| Below is a list of all relevant changes since release 1.6. Older |
| changes are in the file HISTORY. If you are making the jump directly |
| from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the |
| HISTORY file! Many important changes listed there. |
| |
| Alternatively, a good overview of the changes between 1.5.2 and 2.0 is |
| the document "What's New in Python 2.0" by Kuchling and Moshe Zadka: |
| http://starship.python.net/crew/amk/python/writing/new-python/. |
| |
| --Guido van Rossum (home page: http://www.pythonlabs.com/~guido/) |
| |
| ====================================================================== |
| |
| What's new in 2.0 (since release candidate 1)? |
| ============================================== |
| |
| Standard library |
| |
| - The copy_reg module was modified to clarify its intended use: to |
| register pickle support for extension types, not for classes. |
| pickle() will raise a TypeError if it is passed a class. |
| |
| - Fixed a bug in gettext's "normalize and expand" code that prevented |
| it from finding an existing .mo file. |
| |
| - Restored support for HTTP/0.9 servers in httplib. |
| |
| - The math module was changed to stop raising OverflowError in case of |
| underflow, and return 0 instead in underflow cases. Whether Python |
| used to raise OverflowError in case of underflow was platform- |
| dependent (it did when the platform math library set errno to ERANGE |
| on underflow). |
| |
| - Fixed a bug in StringIO that occurred when the file position was not |
| at the end of the file and write() was called with enough data to |
| extend past the end of the file. |
| |
| - Fixed a bug that caused Tkinter error messages to get lost on |
| Windows. The bug was fixed by replacing direct use of |
| interp->result with Tcl_GetStringResult(interp). |
| |
| - Fixed bug in urllib2 that caused it to fail when it received an HTTP |
| redirect response. |
| |
| - Several changes were made to distutils: Some debugging code was |
| removed from util. Fixed the installer used when an external zip |
| program (like WinZip) is not found; the source code for this |
| installer is in Misc/distutils. check_lib() was modified to behave |
| more like AC_CHECK_LIB by add other_libraries() as a parameter. The |
| test for whether installed modules are on sys.path was changed to |
| use both normcase() and normpath(). |
| |
| - Several minor bugs were fixed in the xml package (the minidom, |
| pulldom, expatreader, and saxutils modules). |
| |
| - The regression test driver (regrtest.py) behavior when invoked with |
| -l changed: It now reports a count of objects that are recognized as |
| garbage but not freed by the garbage collector. |
| |
| - The regression test for the math module was changed to test |
| exceptional behavior when the test is run in verbose mode. Python |
| cannot yet guarantee consistent exception behavior across platforms, |
| so the exception part of test_math is run only in verbose mode, and |
| may fail on your platform. |
| |
| Internals |
| |
| - PyOS_CheckStack() has been disabled on Win64, where it caused |
| test_sre to fail. |
| |
| Build issues |
| |
| - Changed compiler flags, so that gcc is always invoked with -Wall and |
| -Wstrict-prototypes. Users compiling Python with GCC should see |
| exactly one warning, except if they have passed configure the |
| --with-pydebug flag. The expected warning is for getopt() in |
| Modules/main.c. This warning will be fixed for Python 2.1. |
| |
| - Fixed configure to add -threads argument during linking on OSF1. |
| |
| Tools and other miscellany |
| |
| - The compiler in Tools/compiler was updated to support the new |
| language features introduced in 2.0: extended print statement, list |
| comprehensions, and augmented assignments. The new compiler should |
| also be backwards compatible with Python 1.5.2; the compiler will |
| always generate code for the version of the interpreter it runs |
| under. |
| |
| What's new in 2.0 release candidate 1 (since beta 2)? |
| ===================================================== |
| |
| What is release candidate 1? |
| |
| We believe that release candidate 1 will fix all known bugs that we |
| intend to fix for the 2.0 final release. This release should be a bit |
| more stable than the previous betas. We would like to see even more |
| widespread testing before the final release, so we are producing this |
| release candidate. The final release will be exactly the same unless |
| any show-stopping (or brown bag) bugs are found by testers of the |
| release candidate. |
| |
| All the changes since the last beta release are bug fixes or changes |
| to support building Python for specific platforms. |
| |
| Core language, builtins, and interpreter |
| |
| - A bug that caused crashes when __coerce__ was used with augmented |
| assignment, e.g. +=, was fixed. |
| |
| - Raise ZeroDivisionError when raising zero to a negative number, |
| e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin |
| power operator and the result of math.pow(0.0, -2.0) will vary by |
| platform. On Linux, it raises a ValueError. |
| |
| - A bug in Unicode string interpolation was fixed that occasionally |
| caused errors with formats including "%%". For example, the |
| following expression "%% %s" % u"abc" no longer raises a TypeError. |
| |
| - Compilation of deeply nested expressions raises MemoryError instead |
| of SyntaxError, e.g. eval("[" * 50 + "]" * 50). |
| |
| - In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode, |
| rendering them useless. They are now written in binary mode again. |
| |
| Standard library |
| |
| - Keyword arguments are now accepted for most pattern and match object |
| methods in SRE, the standard regular expression engine. |
| |
| - In SRE, fixed error with negative lookahead and lookbehind that |
| manifested itself as a runtime error in patterns like "(?<!abc)(def)". |
| |
| - Several bugs in the Unicode handling and error handling in _tkinter |
| were fixed. |
| |
| - Fix memory management errors in Merge() and Tkapp_Call() routines. |
| |
| - Several changes were made to cStringIO to make it compatible with |
| the file-like object interface and with StringIO. If operations are |
| performed on a closed object, an exception is raised. The truncate |
| method now accepts a position argument and readline accepts a size |
| argument. |
| |
| - There were many changes made to the linuxaudiodev module and its |
| test suite; as a result, a short, unexpected audio sample should now |
| play when the regression test is run. |
| |
| Note that this module is named poorly, because it should work |
| correctly on any platform that supports the Open Sound System |
| (OSS). |
| |
| The module now raises exceptions when errors occur instead of |
| crashing. It also defines the AFMT_A_LAW format (logarithmic A-law |
| audio) and defines a getptr() method that calls the |
| SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide. |
| |
| - The library_version attribute, introduced in an earlier beta, was |
| removed because it can not be supported with early versions of the C |
| readline library, which provides no way to determine the version at |
| compile-time. |
| |
| - The binascii module is now enabled on Win64. |
| |
| - tokenize.py no longer suffers "recursion depth" errors when parsing |
| programs with very long string literals. |
| |
| Internals |
| |
| - Fixed several buffer overflow vulnerabilities in calculate_path(), |
| which is called when the interpreter starts up to determine where |
| the standard library is installed. These vulnerabilities affect all |
| previous versions of Python and can be exploited by setting very |
| long values for PYTHONHOME or argv[0]. The risk is greatest for a |
| setuid Python script, although use of the wrapper in |
| Misc/setuid-prog.c will eliminate the vulnerability. |
| |
| - Fixed garbage collection bugs in instance creation that were |
| triggered when errors occurred during initialization. The solution, |
| applied in cPickle and in PyInstance_New(), is to call |
| PyObject_GC_Init() after the initialization of the object's |
| container attributes is complete. |
| |
| - pyexpat adds definitions of PyModule_AddStringConstant and |
| PyModule_AddObject if the Python version is less than 2.0, which |
| provides compatibility with PyXML on Python 1.5.2. |
| |
| - If the platform has a bogus definition for LONG_BIT (the number of |
| bits in a long), an error will be reported at compile time. |
| |
| - Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage |
| collection crashes and possibly other, unreported crashes. |
| |
| - Fixed a memory leak in _PyUnicode_Fini(). |
| |
| Build issues |
| |
| - configure now accepts a --with-suffix option that specifies the |
| executable suffix. This is useful for builds on Cygwin and Mac OS |
| X, for example. |
| |
| - The mmap.PAGESIZE constant is now initialized using sysconf when |
| possible, which eliminates a dependency on -lucb for Reliant UNIX. |
| |
| - The md5 file should now compile on all platforms. |
| |
| - The select module now compiles on platforms that do not define |
| POLLRDNORM and related constants. |
| |
| - Darwin (Mac OS X): Initial support for static builds on this |
| platform. |
| |
| - BeOS: A number of changes were made to the build and installation |
| process. ar-fake now operates on a directory of object files. |
| dl_export.h is gone, and its macros now appear on the mwcc command |
| line during build on PPC BeOS. |
| |
| - Platform directory in lib/python2.0 is "plat-beos5" (or |
| "plat-beos4", if building on BeOS 4.5), rather than "plat-beos". |
| |
| - Cygwin: Support for shared libraries, Tkinter, and sockets. |
| |
| - SunOS 4.1.4_JL: Fix test for directory existence in configure. |
| |
| Tools and other miscellany |
| |
| - Removed debugging prints from main used with freeze. |
| |
| - IDLE auto-indent no longer crashes when it encounters Unicode |
| characters. |
| |
| What's new in 2.0 beta 2 (since beta 1)? |
| ======================================== |
| |
| Core language, builtins, and interpreter |
| |
| - Add support for unbounded ints in %d,i,u,x,X,o formats; for example |
| "%d" % 2L**64 == "18446744073709551616". |
| |
| - Add -h and -V command line options to print the usage message and |
| Python version number and exit immediately. |
| |
| - eval() and exec accept Unicode objects as code parameters. |
| |
| - getattr() and setattr() now also accept Unicode objects for the |
| attribute name, which are converted to strings using the default |
| encoding before lookup. |
| |
| - Multiplication on string and Unicode now does proper bounds |
| checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated |
| string is too long." |
| |
| - Better error message when continue is found in try statement in a |
| loop. |
| |
| |
| Standard library and extensions |
| |
| - socket module: the OpenSSL code now adds support for RAND_status() |
| and EGD (Entropy Gathering Device). |
| |
| - array: reverse() method of array now works. buffer_info() now does |
| argument checking; it still takes no arguments. |
| |
| - asyncore/asynchat: Included most recent version from Sam Rushing. |
| |
| - cgi: Accept '&' or ';' as separator characters when parsing form data. |
| |
| - CGIHTTPServer: Now works on Windows (and perhaps even Mac). |
| |
| - ConfigParser: When reading the file, options spelled in upper case |
| letters are now correctly converted to lowercase. |
| |
| - copy: Copy Unicode objects atomically. |
| |
| - cPickle: Fail gracefully when copy_reg can't be imported. |
| |
| - cStringIO: Implemented readlines() method. |
| |
| - dbm: Add get() and setdefault() methods to dbm object. Add constant |
| `library' to module that names the library used. Added doc strings |
| and method names to error messages. Uses configure to determine |
| which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is |
| now available options. |
| |
| - distutils: Update to version 0.9.3. |
| |
| - dl: Add several dl.RTLD_ constants. |
| |
| - fpectl: Now supported on FreeBSD. |
| |
| - gc: Add DEBUG_SAVEALL option. When enabled all garbage objects |
| found by the collector will be saved in gc.garbage. This is useful |
| for debugging a program that creates reference cycles. |
| |
| - httplib: Three changes: Restore support for set_debuglevel feature |
| of HTTP class. Do not close socket on zero-length response. Do not |
| crash when server sends invalid content-length header. |
| |
| - mailbox: Mailbox class conforms better to qmail specifications. |
| |
| - marshal: When reading a short, sign-extend on platforms where shorts |
| are bigger than 16 bits. When reading a long, repair the unportable |
| sign extension that was being done for 64-bit machines. (It assumed |
| that signed right shift sign-extends.) |
| |
| - operator: Add contains(), invert(), __invert__() as aliases for |
| __contains__(), inv(), and __inv__() respectively. |
| |
| - os: Add support for popen2() and popen3() on all platforms where |
| fork() exists. (popen4() is still in the works.) |
| |
| - os: (Windows only:) Add startfile() function that acts like double- |
| clicking on a file in Explorer (or passing the file name to the |
| DOS "start" command). |
| |
| - os.path: (Windows, DOS:) Treat trailing colon correctly in |
| os.path.join. os.path.join("a:", "b") yields "a:b". |
| |
| - pickle: Now raises ValueError when an invalid pickle that contains |
| a non-string repr where a string repr was expected. This behavior |
| matches cPickle. |
| |
| - posixfile: Remove broken __del__() method. |
| |
| - py_compile: support CR+LF line terminators in source file. |
| |
| - readline: Does not immediately exit when ^C is hit when readline and |
| threads are configured. Adds definition of rl_library_version. (The |
| latter addition requires GNU readline 2.2 or later.) |
| |
| - rfc822: Domain literals returned by AddrlistClass method |
| getdomainliteral() are now properly wrapped in brackets. |
| |
| - site: sys.setdefaultencoding() should only be called in case the |
| standard default encoding ("ascii") is changed. This saves quite a |
| few cycles during startup since the first call to |
| setdefaultencoding() will initialize the codec registry and the |
| encodings package. |
| |
| - socket: Support for size hint in readlines() method of object returned |
| by makefile(). |
| |
| - sre: Added experimental expand() method to match objects. Does not |
| use buffer interface on Unicode strings. Does not hang if group id |
| is followed by whitespace. |
| |
| - StringIO: Size hint in readlines() is now supported as documented. |
| |
| - struct: Check ranges for bytes and shorts. |
| |
| - urllib: Improved handling of win32 proxy settings. Fixed quote and |
| quote_plus functions so that the always encode a comma. |
| |
| - Tkinter: Image objects are now guaranteed to have unique ids. Set |
| event.delta to zero if Tk version doesn't support mousewheel. |
| Removed some debugging prints. |
| |
| - UserList: now implements __contains__(). |
| |
| - webbrowser: On Windows, use os.startfile() instead of os.popen(), |
| which works around a bug in Norton AntiVirus 2000 that leads directly |
| to a Blue Screen freeze. |
| |
| - xml: New version detection code allows PyXML to override standard |
| XML package if PyXML version is greater than 0.6.1. |
| |
| - xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom |
| (conventional DOM), and xml.dom.pulldom, which allows building the DOM |
| tree only for nodes which are sufficiently interesting to a specific |
| application. Does not provide the HTML-specific extensions. Still |
| undocumented. |
| |
| - xml.sax: SAX 2 support for Python, including all the handler |
| interfaces needed to process XML 1.0 compliant XML. Some |
| documentation is already available. |
| |
| - pyexpat: Renamed to xml.parsers.expat since this is part of the new, |
| packagized XML support. |
| |
| |
| C API |
| |
| - Add three new convenience functions for module initialization -- |
| PyModule_AddObject(), PyModule_AddIntConstant(), and |
| PyModule_AddStringConstant(). |
| |
| - Cleaned up definition of NULL in C source code; all definitions were |
| removed and add #error to Python.h if NULL isn't defined after |
| #include of stdio.h. |
| |
| - Py_PROTO() macros that were removed in 2.0b1 have been restored for |
| backwards compatibility (at the source level) with old extensions. |
| |
| - A wrapper API was added for signal() and sigaction(). Instead of |
| either function, always use PyOS_getsig() to get a signal handler |
| and PyOS_setsig() to set one. A new convenience typedef |
| PyOS_sighandler_t is defined for the type of signal handlers. |
| |
| - Add PyString_AsStringAndSize() function that provides access to the |
| internal data buffer and size of a string object -- or the default |
| encoded version of a Unicode object. |
| |
| - PyString_Size() and PyString_AsString() accept Unicode objects. |
| |
| - The standard header <limits.h> is now included by Python.h (if it |
| exists). INT_MAX and LONG_MAX will always be defined, even if |
| <limits.h> is not available. |
| |
| - PyFloat_FromString takes a second argument, pend, that was |
| effectively useless. It is now officially useless but preserved for |
| backwards compatibility. If the pend argument is not NULL, *pend is |
| set to NULL. |
| |
| - PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects |
| for the attribute name. See note on getattr() above. |
| |
| - A few bug fixes to argument processing for Unicode. |
| PyArg_ParseTupleAndKeywords() now accepts "es#" and "es". |
| PyArg_Parse() special cases "s#" for Unicode objects; it returns a |
| pointer to the default encoded string data instead of to the raw |
| UTF-16. |
| |
| - Py_BuildValue accepts B format (for bgen-generated code). |
| |
| |
| Internals |
| |
| - On Unix, fix code for finding Python installation directory so that |
| it works when argv[0] is a relative path. |
| |
| - Added a true unicode_internal_encode() function and fixed the |
| unicode_internal_decode function() to support Unicode objects directly |
| rather than by generating a copy of the object. |
| |
| - Several of the internal Unicode tables are much smaller now, and |
| the source code should be much friendlier to weaker compilers. |
| |
| - In the garbage collector: Fixed bug in collection of tuples. Fixed |
| bug that caused some instances to be removed from the container set |
| while they were still live. Fixed parsing in gc.set_debug() for |
| platforms where sizeof(long) > sizeof(int). |
| |
| - Fixed refcount problem in instance deallocation that only occurred |
| when Py_REF_DEBUG was defined and Py_TRACE_REFS was not. |
| |
| - On Windows, getpythonregpath is now protected against null data in |
| registry key. |
| |
| - On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race |
| condition. |
| |
| |
| Build and platform-specific issues |
| |
| - Better support of GNU Pth via --with-pth configure option. |
| |
| - Python/C API now properly exposed to dynamically-loaded extension |
| modules on Reliant UNIX. |
| |
| - Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c: |
| Don't define MS_SYNC to be zero when it is undefined. Added missing |
| prototypes in posixmodule.c. |
| |
| - Improved support for HP-UX build. Threads should now be correctly |
| configured (on HP-UX 10.20 and 11.00). |
| |
| - Fix largefile support on older NetBSD systems and OpenBSD by adding |
| define for TELL64. |
| |
| |
| Tools and other miscellany |
| |
| - ftpmirror: Call to main() is wrapped in if __name__ == "__main__". |
| |
| - freeze: The modulefinder now works with 2.0 opcodes. |
| |
| - IDLE: |
| Move hackery of sys.argv until after the Tk instance has been |
| created, which allows the application-specific Tkinter |
| initialization to be executed if present; also pass an explicit |
| className parameter to the Tk() constructor. |
| |
| |
| What's new in 2.0 beta 1? |
| ========================= |
| |
| Source Incompatibilities |
| ------------------------ |
| |
| None. Note that 1.6 introduced several incompatibilities with 1.5.2, |
| such as single-argument append(), connect() and bind(), and changes to |
| str(long) and repr(float). |
| |
| |
| Binary Incompatibilities |
| ------------------------ |
| |
| - Third party extensions built for Python 1.5.x or 1.6 cannot be used |
| with Python 2.0; these extensions will have to be rebuilt for Python |
| 2.0. |
| |
| - On Windows, attempting to import a third party extension built for |
| Python 1.5.x or 1.6 results in an immediate crash; there's not much we |
| can do about this. Check your PYTHONPATH environment variable! |
| |
| - Python bytecode files (*.pyc and *.pyo) are not compatible between |
| releases. |
| |
| |
| Overview of Changes Since 1.6 |
| ----------------------------- |
| |
| There are many new modules (including brand new XML support through |
| the xml package, and i18n support through the gettext module); a list |
| of all new modules is included below. Lots of bugs have been fixed. |
| |
| The process for making major new changes to the language has changed |
| since Python 1.6. Enhancements must now be documented by a Python |
| Enhancement Proposal (PEP) before they can be accepted. |
| |
| There are several important syntax enhancements, described in more |
| detail below: |
| |
| - Augmented assignment, e.g. x += 1 |
| |
| - List comprehensions, e.g. [x**2 for x in range(10)] |
| |
| - Extended import statement, e.g. import Module as Name |
| |
| - Extended print statement, e.g. print >> file, "Hello" |
| |
| Other important changes: |
| |
| - Optional collection of cyclical garbage |
| |
| Python Enhancement Proposal (PEP) |
| --------------------------------- |
| |
| PEP stands for Python Enhancement Proposal. A PEP is a design |
| document providing information to the Python community, or describing |
| a new feature for Python. The PEP should provide a concise technical |
| specification of the feature and a rationale for the feature. |
| |
| We intend PEPs to be the primary mechanisms for proposing new |
| features, for collecting community input on an issue, and for |
| documenting the design decisions that have gone into Python. The PEP |
| author is responsible for building consensus within the community and |
| documenting dissenting opinions. |
| |
| The PEPs are available at http://python.sourceforge.net/peps/. |
| |
| Augmented Assignment |
| -------------------- |
| |
| This must have been the most-requested feature of the past years! |
| Eleven new assignment operators were added: |
| |
| += -= *= /= %= **= <<= >>= &= ^= |= |
| |
| For example, |
| |
| A += B |
| |
| is similar to |
| |
| A = A + B |
| |
| except that A is evaluated only once (relevant when A is something |
| like dict[index].attr). |
| |
| However, if A is a mutable object, A may be modified in place. Thus, |
| if A is a number or a string, A += B has the same effect as A = A+B |
| (except A is only evaluated once); but if a is a list, A += B has the |
| same effect as A.extend(B)! |
| |
| Classes and built-in object types can override the new operators in |
| order to implement the in-place behavior; the not-in-place behavior is |
| used automatically as a fallback when an object doesn't implement the |
| in-place behavior. For classes, the method name is derived from the |
| method name for the corresponding not-in-place operator by inserting |
| an 'i' in front of the name, e.g. __iadd__ implements in-place |
| __add__. |
| |
| Augmented assignment was implemented by Thomas Wouters. |
| |
| |
| List Comprehensions |
| ------------------- |
| |
| This is a flexible new notation for lists whose elements are computed |
| from another list (or lists). The simplest form is: |
| |
| [<expression> for <variable> in <sequence>] |
| |
| For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9]. |
| This is more efficient than a for loop with a list.append() call. |
| |
| You can also add a condition: |
| |
| [<expression> for <variable> in <sequence> if <condition>] |
| |
| For example, [w for w in words if w == w.lower()] would yield the list |
| of words that contain no uppercase characters. This is more efficient |
| than a for loop with an if statement and a list.append() call. |
| |
| You can also have nested for loops and more than one 'if' clause. For |
| example, here's a function that flattens a sequence of sequences:: |
| |
| def flatten(seq): |
| return [x for subseq in seq for x in subseq] |
| |
| flatten([[0], [1,2,3], [4,5], [6,7,8,9], []]) |
| |
| This prints |
| |
| [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| |
| List comprehensions originated as a patch set from Greg Ewing; Skip |
| Montanaro and Thomas Wouters also contributed. Described by PEP 202. |
| |
| |
| Extended Import Statement |
| ------------------------- |
| |
| Many people have asked for a way to import a module under a different |
| name. This can be accomplished like this: |
| |
| import foo |
| bar = foo |
| del foo |
| |
| but this common idiom gets old quickly. A simple extension of the |
| import statement now allows this to be written as follows: |
| |
| import foo as bar |
| |
| There's also a variant for 'from ... import': |
| |
| from foo import bar as spam |
| |
| This also works with packages; e.g. you can write this: |
| |
| import test.regrtest as regrtest |
| |
| Note that 'as' is not a new keyword -- it is recognized only in this |
| context (this is only possible because the syntax for the import |
| statement doesn't involve expressions). |
| |
| Implemented by Thomas Wouters. Described by PEP 221. |
| |
| |
| Extended Print Statement |
| ------------------------ |
| |
| Easily the most controversial new feature, this extension to the print |
| statement adds an option to make the output go to a different file |
| than the default sys.stdout. |
| |
| For example, to write an error message to sys.stderr, you can now |
| write: |
| |
| print >> sys.stderr, "Error: bad dog!" |
| |
| As a special feature, if the expression used to indicate the file |
| evaluates to None, the current value of sys.stdout is used. Thus: |
| |
| print >> None, "Hello world" |
| |
| is equivalent to |
| |
| print "Hello world" |
| |
| Design and implementation by Barry Warsaw. Described by PEP 214. |
| |
| |
| Optional Collection of Cyclical Garbage |
| --------------------------------------- |
| |
| Python is now equipped with a garbage collector that can hunt down |
| cyclical references between Python objects. It's no replacement for |
| reference counting; in fact, it depends on the reference counts being |
| correct, and decides that a set of objects belong to a cycle if all |
| their reference counts can be accounted for from their references to |
| each other. This devious scheme was first proposed by Eric Tiedemann, |
| and brought to implementation by Neil Schemenauer. |
| |
| There's a module "gc" that lets you control some parameters of the |
| garbage collection. There's also an option to the configure script |
| that lets you enable or disable the garbage collection. In 2.0b1, |
| it's on by default, so that we (hopefully) can collect decent user |
| experience with this new feature. There are some questions about its |
| performance. If it proves to be too much of a problem, we'll turn it |
| off by default in the final 2.0 release. |
| |
| |
| Smaller Changes |
| --------------- |
| |
| A new function zip() was added. zip(seq1, seq2, ...) is equivalent to |
| map(None, seq1, seq2, ...) when the sequences have the same length; |
| i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When |
| the lists are not all the same length, the shortest list wins: |
| zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201. |
| |
| sys.version_info is a tuple (major, minor, micro, level, serial). |
| |
| Dictionaries have an odd new method, setdefault(key, default). |
| dict.setdefault(key, default) returns dict[key] if it exists; if not, |
| it sets dict[key] to default and returns that value. Thus: |
| |
| dict.setdefault(key, []).append(item) |
| |
| does the same work as this common idiom: |
| |
| if not dict.has_key(key): |
| dict[key] = [] |
| dict[key].append(item) |
| |
| There are two new variants of SyntaxError that are raised for |
| indentation-related errors: IndentationError and TabError. |
| |
| Changed \x to consume exactly two hex digits; see PEP 223. Added \U |
| escape that consumes exactly eight hex digits. |
| |
| The limits on the size of expressions and file in Python source code |
| have been raised from 2**16 to 2**32. Previous versions of Python |
| were limited because the maximum argument size the Python VM accepted |
| was 2**16. This limited the size of object constructor expressions, |
| e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This |
| limit was raised thanks to a patch by Charles Waldman that effectively |
| fixes the problem. It is now much more likely that you will be |
| limited by available memory than by an arbitrary limit in Python. |
| |
| The interpreter's maximum recursion depth can be modified by Python |
| programs using sys.getrecursionlimit and sys.setrecursionlimit. This |
| limit is the maximum number of recursive calls that can be made by |
| Python code. The limit exists to prevent infinite recursion from |
| overflowing the C stack and causing a core dump. The default value is |
| 1000. The maximum safe value for a particular platform can be found |
| by running Misc/find_recursionlimit.py. |
| |
| New Modules and Packages |
| ------------------------ |
| |
| atexit - for registering functions to be called when Python exits. |
| |
| imputil - Greg Stein's alternative API for writing custom import |
| hooks. |
| |
| pyexpat - an interface to the Expat XML parser, contributed by Paul |
| Prescod. |
| |
| xml - a new package with XML support code organized (so far) in three |
| subpackages: xml.dom, xml.sax, and xml.parsers. Describing these |
| would fill a volume. There's a special feature whereby a |
| user-installed package named _xmlplus overrides the standard |
| xmlpackage; this is intended to give the XML SIG a hook to distribute |
| backwards-compatible updates to the standard xml package. |
| |
| webbrowser - a platform-independent API to launch a web browser. |
| |
| |
| Changed Modules |
| --------------- |
| |
| array -- new methods for array objects: count, extend, index, pop, and |
| remove |
| |
| binascii -- new functions b2a_hex and a2b_hex that convert between |
| binary data and its hex representation |
| |
| calendar -- Many new functions that support features including control |
| over which day of the week is the first day, returning strings instead |
| of printing them. Also new symbolic constants for days of week, |
| e.g. MONDAY, ..., SUNDAY. |
| |
| cgi -- FieldStorage objects have a getvalue method that works like a |
| dictionary's get method and returns the value attribute of the object. |
| |
| ConfigParser -- The parser object has new methods has_option, |
| remove_section, remove_option, set, and write. They allow the module |
| to be used for writing config files as well as reading them. |
| |
| ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now |
| optionally support the RFC 959 REST command. |
| |
| gzip -- readline and readlines now accept optional size arguments |
| |
| httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See |
| the module doc strings for details. |
| |
| locale -- implement getdefaultlocale for Win32 and Macintosh |
| |
| marshal -- no longer dumps core when marshaling deeply nested or |
| recursive data structures |
| |
| os -- new functions isatty, seteuid, setegid, setreuid, setregid |
| |
| os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3 |
| support under Unix. |
| |
| os/pty -- support for openpty and forkpty |
| |
| os.path -- fix semantics of os.path.commonprefix |
| |
| smtplib -- support for sending very long messages |
| |
| socket -- new function getfqdn() |
| |
| readline -- new functions to read, write and truncate history files. |
| The readline section of the library reference manual contains an |
| example. |
| |
| select -- add interface to poll system call |
| |
| shutil -- new copyfileobj function |
| |
| SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the |
| HTTP server. |
| |
| Tkinter -- optimization of function flatten |
| |
| urllib -- scans environment variables for proxy configuration, |
| e.g. http_proxy. |
| |
| whichdb -- recognizes dumbdbm format |
| |
| |
| Obsolete Modules |
| ---------------- |
| |
| None. However note that 1.6 made a whole slew of modules obsolete: |
| stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail, |
| poly, zmod, strop, util, whatsound. |
| |
| |
| Changed, New, Obsolete Tools |
| ---------------------------- |
| |
| None. |
| |
| |
| C-level Changes |
| --------------- |
| |
| Several cleanup jobs were carried out throughout the source code. |
| |
| All C code was converted to ANSI C; we got rid of all uses of the |
| Py_PROTO() macro, which makes the header files a lot more readable. |
| |
| Most of the portability hacks were moved to a new header file, |
| pyport.h; several other new header files were added and some old |
| header files were removed, in an attempt to create a more rational set |
| of header files. (Few of these ever need to be included explicitly; |
| they are all included by Python.h.) |
| |
| Trent Mick ensured portability to 64-bit platforms, under both Linux |
| and Win64, especially for the new Intel Itanium processor. Mick also |
| added large file support for Linux64 and Win64. |
| |
| The C APIs to return an object's size have been update to consistently |
| use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In |
| previous versions, the abstract interfaces used PyXXX_Length and the |
| concrete interfaces used PyXXX_Size. The old names, |
| e.g. PyObject_Length, are still available for backwards compatibility |
| at the API level, but are deprecated. |
| |
| The PyOS_CheckStack function has been implemented on Windows by |
| Fredrik Lundh. It prevents Python from failing with a stack overflow |
| on Windows. |
| |
| The GC changes resulted in creation of two new slots on object, |
| tp_traverse and tp_clear. The augmented assignment changes result in |
| the creation of a new slot for each in-place operator. |
| |
| The GC API creates new requirements for container types implemented in |
| C extension modules. See Include/objimpl.h for details. |
| |
| PyErr_Format has been updated to automatically calculate the size of |
| the buffer needed to hold the formatted result string. This change |
| prevents crashes caused by programmer error. |
| |
| New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable. |
| |
| PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions |
| that are the same as their non-Ex counterparts except they take an |
| extra flag argument that tells them to close the file when done. |
| |
| XXX There were other API changes that should be fleshed out here. |
| |
| |
| Windows Changes |
| --------------- |
| |
| New popen2/popen3/peopen4 in os module (see Changed Modules above). |
| |
| os.popen is much more usable on Windows 95 and 98. See Microsoft |
| Knowledge Base article Q150956. The Win9x workaround described there |
| is implemented by the new w9xpopen.exe helper in the root of your |
| Python installation. Note that Python uses this internally; it is not |
| a standalone program. |
| |
| Administrator privileges are no longer required to install Python |
| on Windows NT or Windows 2000. If you have administrator privileges, |
| Python's registry info will be written under HKEY_LOCAL_MACHINE. |
| Otherwise the installer backs off to writing Python's registry info |
| under HKEY_CURRENT_USER. The latter is sufficient for all "normal" |
| uses of Python, but will prevent some advanced uses from working |
| (for example, running a Python script as an NT service, or possibly |
| from CGI). |
| |
| [This was new in 1.6] The installer no longer runs a separate Tcl/Tk |
| installer; instead, it installs the needed Tcl/Tk files directly in the |
| Python directory. If you already have a Tcl/Tk installation, this |
| wastes some disk space (about 4 Megs) but avoids problems with |
| conflicting Tcl/Tk installations, and makes it much easier for Python |
| to ensure that Tcl/Tk can find all its files. |
| |
| [This was new in 1.6] The Windows installer now installs by default in |
| \Python20\ on the default volume, instead of \Program Files\Python-2.0\. |
| |
| |
| Updates to the changes between 1.5.2 and 1.6 |
| -------------------------------------------- |
| |
| The 1.6 NEWS file can't be changed after the release is done, so here |
| is some late-breaking news: |
| |
| New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(), |
| and changes to getlocale() and setlocale(). |
| |
| The new module is now enabled per default. |
| |
| It is not true that the encodings codecs cannot be used for normal |
| strings: the string.encode() (which is also present on 8-bit strings |
| !) allows using them for 8-bit strings too, e.g. to convert files from |
| cp1252 (Windows) to latin-1 or vice-versa. |
| |
| Japanese codecs are available from Tamito KAJIYAMA: |
| http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/ |
| |
| |
| ====================================================================== |