/usr/lib/python2.7/dist-packages/txdav/carddav/ is in calendarserver 5.2+dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/txdav/carddav/__init__.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/__init__.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/file.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/index_file.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/sql.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/__init__.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/common.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/test_file.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/test_index_file.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/test/test_sql.py
/usr/lib/python2.7/dist-packages/txdav/carddav/datastore/util.py
/usr/lib/python2.7/dist-packages/txdav/carddav/iaddressbookstore.py
/usr/lib/python2.7/dist-packages/txdav/carddav/resource.py