Python News

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What's New in Python 2.3.3 (final)?

Release date: 19-Dec-2003

Core and builtins

  • Removed PendingDeprecationWarning from apply(). apply() remains deprecated, but the nuisance warning will not be issued.

Library

  • A couple of bugs were squished in trace.py

What's New in Python 2.3.3c1?

Release date: 05-Dec-2003

Core and builtins

  • Critical bugfix, for SF bug 839548: if a weakref with a callback, its callback, and its weakly referenced object, all became part of cyclic garbage during a single run of garbage collection, the order in which they were torn down was unpredictable. It was possible for the callback to see partially-torn-down objects, leading to immediate segfaults, or, if the callback resurrected garbage objects, to resurrect insane objects that caused segfaults (or other surprises) later. In one sense this wasn't surprising, because Python's cyclic gc had no knowledge of Python's weakref objects. It does now. When weakrefs with callbacks become part of cyclic garbage now, those weakrefs are cleared first. The callbacks don't trigger then, preventing the problems. If you need callbacks to trigger, then just as when cyclic gc is not involved, you need to write your code so that weakref objects outlive the objects they weakly reference.
  • Critical bugfix, for SF bug 840829: if cyclic garbage collection happened to occur during a weakref callback for a new-style class instance, subtle memory corruption could result (in a release build; in a debug build, a segfault occurred reliably very soon after). This has been repaired.
  • At Python shutdown time (Py_Finalize()), 2.3 called cyclic garbage collection twice, both before and after tearing down modules. The call after tearing down modules has been disabled, because too much of Python has been torn down then for __del__ methods and weakref callbacks to execute sanely. The most common symptom was a sequence of uninformative messages on stderr when Python shut down, produced by threads trying to raise exceptions, but unable to report the nature of their problems because too much of the sys module had already been destroyed.
  • Patch #820195: object.__contains__() now returns True or False instead of 1 or 0.

Extension modules

  • Bug #852314: Fix return type of tkFileDialog.askdirectory on Unix.
  • Bug #834676: Fix crashes when normalizing Hangul syllables.
  • Bug #703198: Ignore "b" and "t" in os.popen on Unix.
  • Patch #803998: Deal with errors in SSL_write correctly.
  • The xml.parsers.expat module now provides Expat 1.95.7.
  • Patch #813445: Add missing socket.IPPROTO_IPV6.
  • Bug #807314: Properly raise an exception if non-existent Tcl variable is accessed.
  • Bug #811028: ncurses.h breakage on FreeBSD/MacOS X
  • Bug #814613: INET_ADDRSTRLEN fix needed for all compilers on SGI

Library

  • Bug #849662: UserDict.DictMixin had performance issues when an instance was tested for equality with None.
  • Bug #848614: distutils' msvccompiler fails to find the MSVC6 compiler because of incomplete registry entries.
  • Patch #841977: modulefinder didn't find extension modules in packages.
  • Bug #792101: Add missing file operations for httplib.SSLFile.
  • Bug #811082: test_tempfile fails if space in install directory.
  • Bug #780461: platform.mac_ver() raised MacOSError exception under OS X.
  • Bug #812202: random.randrange() returned only even numbers for range lengths above 2**53.
  • Bug #823328: urllib2's HTTP Digest Auth support works again.