The registry really does seem to be the most common use case: http://ivansmirnov.io/python-metaclasses/#metaclass-as-a-registry http://ivansmirnov.io/python-me

The registry really does seem to be the most common use case: http://ivansmirnov.io/python-metaclasses/#metaclass-as-a-registry http://ivansmirnov.io/python-metaclasses/#metaclass-as-a-reg... This enables things like plugin systems, where you want the act of importing a plugin which defines some objects to load those objects into the available plugin list.