/usr/lib/python2.7/dist-packages/z3c.pt-2.2.3-nspkg.pth is in python-z3c.pt 2.2.3-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/../../../share/pyshared/z3c.pt-2.2.3-nspkg.pth