/usr/lib/python2.7/dist-packages/gobject/propertyhelper.py is in python-gobject-2 2.28.6-12+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/gobject/../../../../share/pyshared/gobject/propertyhelper.py