/usr/lib/python2.7/dist-packages/zope/principalregistry/metadirectives.py is in python-zope.principalregistry 3.7.1-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/zope/principalregistry/../../../../../share/pyshared/zope/principalregistry/metadirectives.py