In multiprocessing.connection, when using a Windows named pipe on a Unix platform, the following error will occur. This should not happen, the format of the address should be validated somehow before. The following error will occur because PipeListener is not defined under any platform different than win32. 

Python 3.2.2 (default, Oct 14 2011, 21:46:49)
[GCC 4.2.2 20070831 prerelease [FreeBSD]] on freebsd8
Type "help", "copyright", "credits" or "license" for more information.
>>> from multiprocessing.connection import Listener
>>> Listener(r'\\.\test')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/multiprocessing/connection.py", line 130, in __init__
    self._listener = PipeListener(address, backlog)
NameError: global name 'PipeListener' is not defined
>>>


I've attached a small patch for this issue.

Thanks for the patch. I don't think it deserves to be a public API (it could be a private function, i.e. starting with an underscore).
Also, it's better if you can add a test (to Lib/test/test_multiprocessing.py) checking that ValueError is raised when applicable.

Here are the two diffs. Hope they are good this time.

New changeset 273d7502ced1 by Antoine Pitrou in branch '3.2':
Issue #14151: Raise a ValueError, not a NameError, when trying to create
http://hg.python.org/cpython/rev/273d7502ced1

New changeset 42b29aea1c98 by Antoine Pitrou in branch 'default':
Issue #14151: Raise a ValueError, not a NameError, when trying to create
http://hg.python.org/cpython/rev/42b29aea1c98

Thank you!
For the record, the recommended workflow to produce patches is to use Mercurial: see http://docs.python.org/devguide/setup.html#getting-the-source-code
so that you only have to type e.g. "hg diff" to get a diff of all your local changes.