"""Container overriding example.""" from dependency_injector import containers, providers class Service: ... class ServiceStub: ... class Container(containers.DeclarativeContainer): service = providers.Factory(Service) class OverridingContainer(containers.DeclarativeContainer): service = providers.Factory(ServiceStub) if __name__ == '__main__': container = Container() overriding_container = OverridingContainer() container.override(overriding_container) service = container.service() assert isinstance(service, ServiceStub)