/usr/lib/python2.7/dist-packages/sympy/sets/ is in python-sympy 1.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/sympy/sets/__init__.py
/usr/lib/python2.7/dist-packages/sympy/sets/conditionset.py
/usr/lib/python2.7/dist-packages/sympy/sets/contains.py
/usr/lib/python2.7/dist-packages/sympy/sets/fancysets.py
/usr/lib/python2.7/dist-packages/sympy/sets/sets.py
/usr/lib/python2.7/dist-packages/sympy/sets/tests/
/usr/lib/python2.7/dist-packages/sympy/sets/tests/__init__.py
/usr/lib/python2.7/dist-packages/sympy/sets/tests/test_conditionset.py
/usr/lib/python2.7/dist-packages/sympy/sets/tests/test_contains.py
/usr/lib/python2.7/dist-packages/sympy/sets/tests/test_fancysets.py
/usr/lib/python2.7/dist-packages/sympy/sets/tests/test_sets.py