lib/python2.7/site-packages/ruamel.ordereddict-0.4.13-py2.7-nspkg.pth says:
import sys, types, os;p = os.path.join(sys._getframe(1).f_locals['sitedir'], *('ruamel',));ie = os.path.exists(os.path.join(p,'__init__.py'));m = not ie and sys.modules.setdefault('ruamel', types.ModuleType('ruamel'));mp = (m or []) and m.__dict__.setdefault('__path__',[]);(p not in mp) and mp.append(p)