/usr/lib/python2.7/dist-packages/DNS/Lib.py is in python-dns 2.3.6-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/DNS/../../../../share/pyshared/DNS/Lib.py
/usr/lib/python2.7/dist-packages/DNS/../../../../share/pyshared/DNS/Lib.py