Python 3.0 的第三个 RC 版本今天发布了，正式版预计在十二月份的时候出。
该版本主要修正了 RC2 的一些bug，详细内容如下：
- Issue #4349: sys.path included a non-existent platform directory because of a
- Issue #3327: Don't overallocate in the modules_by_index list.
- Issue #1721812: Binary set operations and copy() returned the input type instead of the appropriate base type. This was incorrect because set subclasses would be created without their __init__() method being called. The corrected behavior brings sets into line with lists and dicts.
- Issue #4296: Fix PyObject_RichCompareBool so that "x in [x]" evaluates to True, even when x doesn't compare equal to itself. This was a regression from 2.6.
- Issue #3705: Command-line arguments were not correctly decoded when the terminal does not use UTF8.
- Issue #3799: Fix dbm.dumb to accept strings as well as bytes for keys. String keys are now written out in UTF-8.
- Issue #4338: Fix distutils upload command.
- Issue #4354: Fix distutils register command.
- Issue #4116: Resolve member name conflict in ScrolledCanvas.__init__.
- Issue #4307: The named tuple that ``inspect.getfullargspec()`` returns now uses ``kwonlydefaults`` instead of ``kwdefaults``.
- Issue #4298: Fix a segfault when pickle.loads is passed a ill-formed input.
- Issue #4283: Fix a left-over "iteritems" call in distutils.
- Issue #4289: Remove Cancel button from AdvancedDlg.
- Issue #1656675: Register a drop handler for .py* files on Windows.
- Demos of the socketserver module now work with Python 3.