I never really noticed that before, but Source.Python's log messages aren't showing their origin.
Example log message:
2017-07-04 20:35:55 - sp - DEBUG OnEntityDeleted.__init__<<function _on_entity_deleted at 0x1CD16228>>
It's sent by listeners_logger, so the log message should actually say the following:
2017-07-04 20:35:55 - sp.listeners - DEBUG OnEntityDeleted.__init__<<function _on_entity_deleted at 0x1CD16228>>