/usr/lib/python2.7/dist-packages/zope/principalregistry/ is in python-zope.principalregistry 3.7.1-0ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/zope/principalregistry/README.txt
/usr/lib/python2.7/dist-packages/zope/principalregistry/__init__.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/configure.zcml
/usr/lib/python2.7/dist-packages/zope/principalregistry/meta.zcml
/usr/lib/python2.7/dist-packages/zope/principalregistry/metaconfigure.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/metadirectives.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/principalregistry.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/tests/
/usr/lib/python2.7/dist-packages/zope/principalregistry/tests/__init__.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/tests/principal.zcml
/usr/lib/python2.7/dist-packages/zope/principalregistry/tests/test_doc.py
/usr/lib/python2.7/dist-packages/zope/principalregistry/tests/test_principalregistry.py