/usr/lib/python2.7/dist-packages/logilab/astng/as_string.py is in python-logilab-astng 0.23.0-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/logilab/astng/../../../../../share/pyshared/logilab/astng/as_string.py