/usr/lib/python2.7/dist-packages/xmpp/session.py is in python-xmpp 0.4.1-cvs20080505.2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/xmpp/../../../../share/pyshared/xmpp/session.py