/usr/lib/python2.7/dist-packages/yaml/ is in python-yaml 3.10-2ubuntu0.1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/yaml/__init__.py
/usr/lib/python2.7/dist-packages/yaml/composer.py
/usr/lib/python2.7/dist-packages/yaml/constructor.py
/usr/lib/python2.7/dist-packages/yaml/cyaml.py
/usr/lib/python2.7/dist-packages/yaml/dumper.py
/usr/lib/python2.7/dist-packages/yaml/emitter.py
/usr/lib/python2.7/dist-packages/yaml/error.py
/usr/lib/python2.7/dist-packages/yaml/events.py
/usr/lib/python2.7/dist-packages/yaml/loader.py
/usr/lib/python2.7/dist-packages/yaml/nodes.py
/usr/lib/python2.7/dist-packages/yaml/parser.py
/usr/lib/python2.7/dist-packages/yaml/reader.py
/usr/lib/python2.7/dist-packages/yaml/representer.py
/usr/lib/python2.7/dist-packages/yaml/resolver.py
/usr/lib/python2.7/dist-packages/yaml/scanner.py
/usr/lib/python2.7/dist-packages/yaml/serializer.py
/usr/lib/python2.7/dist-packages/yaml/tokens.py