/usr/lib/python3/dist-packages/networkx/algorithms/flow/ is in python3-networkx 1.9+dfsg1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python3/dist-packages/networkx/algorithms/flow/__init__.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/capacityscaling.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/edmondskarp.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/fordfulkerson.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/maxflow.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/mincost.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/networksimplex.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/preflowpush.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/shortestaugmentingpath.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/gl1.gpickle.bz2
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/gw1.gpickle.bz2
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/test_maxflow.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/test_maxflow_large_graph.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/test_mincost.py
/usr/lib/python3/dist-packages/networkx/algorithms/flow/tests/wlm3.gpickle.bz2
/usr/lib/python3/dist-packages/networkx/algorithms/flow/utils.py