/usr/lib/python2.7/dist-packages/aptdaemon/gtk3widgets.py is in python-aptdaemon.gtk3widgets 0.43+bzr805-0ubuntu10.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/aptdaemon/../../../../share/pyshared/aptdaemon/gtk3widgets.py