Thanks for the patch.

I think we can move the Python 3 part of the patch to a new note directive (similar to the example in httplib documentation: https://docs.python.org/2/library/httplib.html)

For example:

.. deprecated:: 2.6
   Use :mode:`HTMLParser` instead.

.. note::
   The :mod:`htmllib` module has been removed in Python 3.  Use :mod:`html.parser` (equivalent of :mode:`HTMLParser`) instead.