/usr/share/pyshared/zope.app.principalannotation-3.7.1.egg-info/namespace_packages.txt is in python-zope.app.principalannotation 3.7.1-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | zope
zope.app
|