Spelling it out with an example: If the propagate attribute of the logger named ``A.B.C`` evaluates to true, any event logged to ``A.B.C`` via a method call such as ``logging.getLogger('A.B.C').error(...)`` will [subject to passing that logger's level and filter settings] be passed in turn to any handlers attached to loggers named ``A.B``, ``A`` and the root logger, after first being passed to any handlers attached to ``A.B.C``. If any logger in the chain ``A.B.C``, ``A.B``, ``A`` has its ``propagate`` attribute set to false, then that is the last logger whose handlers are offered the event to handle, and propagation stops at that point.