/usr/lib/python2.7/dist-packages/sympy/external/ is in python-sympy 1.1.1-5.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/sympy/external/__init__.py
/usr/lib/python2.7/dist-packages/sympy/external/importtools.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/
/usr/lib/python2.7/dist-packages/sympy/external/tests/__init__.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_autowrap.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_codegen.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_importtools.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_numpy.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_sage.py
/usr/lib/python2.7/dist-packages/sympy/external/tests/test_scipy.py