/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/ is in python3-networkx 1.8.1-0ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/__init__.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/adjacency.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/node_link.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/serialize.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tests/
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tests/test_adjacency.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tests/test_node_link.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tests/test_serialize.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tests/test_tree.py
/usr/lib/python3/dist-packages/networkx/readwrite/json_graph/tree.py