I have written a patch against the current Python trunk's gettext to
add support for pgettext and friends (upgettext, npgettext, unpgettext,
...).

I have also changed Tools/i18n/msgfmt.py to recognize the "msgctxt" keyword.
Some new unittests for dgettext and lgettext and variants are also included.

If the patch will be accepted then someone should drop a message to the
maintainers of GNU gettext to add the new functions as default keywords
for xgettext. Right now you have to call xgettext with
"--keyword=pgettext:1c,2" to extract messages with context. 

Tools/i18n/pygettext.py does currently not handle context variants.