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Python 3.3.5 release

Python 3.3.5

Note: A newer security-fix release, 3.3.6, is currently available. Its use is recommended.

Python 3.3.5 was released on March 9th, 2014.

Python 3.3.5 includes fixes for these important issues:

and also fixes quite a few other bugs.

This release fully supports OS X 10.9 Mavericks. In particular, this release fixes an issue that could cause previous versions of Python to crash when typing in interactive mode on OS X 10.9.

Major new features of the 3.3 series, compared to 3.2

Python 3.3 includes a range of improvements of the 3.x series, as well as easier porting between 2.x and 3.x.

  • PEP 380, syntax for delegating to a subgenerator (yield from)
  • PEP 393, flexible string representation (doing away with the distinction between "wide" and "narrow" Unicode builds)
  • A C implementation of the "decimal" module, with up to 120x speedup for decimal-heavy applications
  • The import system (__import__) is based on importlib by default
  • The new "lzma" module with LZMA/XZ support
  • PEP 397, a Python launcher for Windows
  • PEP 405, virtual environment support in core
  • PEP 420, namespace package support
  • PEP 3151, reworking the OS and IO exception hierarchy
  • PEP 3155, qualified name for classes and functions
  • PEP 409, suppressing exception context
  • PEP 414, explicit Unicode literals to help with porting
  • PEP 418, extended platform-independent clocks in the "time" module
  • PEP 412, a new key-sharing dictionary implementation that significantly saves memory for object-oriented code
  • PEP 362, the function-signature object
  • The new "faulthandler" module that helps diagnosing crashes
  • The new "unittest.mock" module
  • The new "ipaddress" module
  • The "sys.implementation" attribute
  • A policy framework for the email package, with a provisional (see PEP 411) policy that adds much improved unicode support for email header parsing
  • A "collections.ChainMap" class for linking mappings to a single unit
  • Wrappers for many more POSIX functions in the "os" and "signal" modules, as well as other useful functions such as "sendfile()"
  • Hash randomization, introduced in earlier bugfix releases, is now switched on by default


This is a production release. Please report any bugs you encounter.

Please proceed to the download page for the download.