In watcher project, some py file use "from oslo_log import log as logging" for import, but more use "from oslo_log import log" like https://github.com/openstack/watcher/blob/master/watcher/decision_engine/strategy/strategies/dummy_strategy.py#L19 this patch to unify it. Change-Id: I9c667bb202bebc7942d1af5ce438375285c2e2ba