"""Catalog overriding example.""" import collections import dependency_injector as di # Creating some example classes: Object1 = collections.namedtuple('Object1', ['arg1', 'arg2']) Object2 = collections.namedtuple('Object2', ['object1']) ExtendedObject2 = collections.namedtuple('ExtendedObject2', []) class Catalog(di.DeclarativeCatalog): """Providers catalog.""" object1_factory = di.Factory(Object1, arg1=1, arg2=2) """:type: di.Provider -> Object1""" object2_factory = di.Factory(Object2, object1=object1_factory) """:type: di.Provider -> Object2""" class AnotherCatalog(di.DeclarativeCatalog): """Another providers catalog.""" object2_factory = di.Factory(ExtendedObject2) """:type: di.Provider -> ExtendedObject2""" # Overriding `Catalog` with `AnotherCatalog`: Catalog.override(AnotherCatalog) # Creating some objects using overridden catalog: object2_1 = Catalog.object2_factory() object2_2 = Catalog.object2_factory() # Making some asserts: assert object2_1 is not object2_2 assert isinstance(object2_1, ExtendedObject2) assert isinstance(object2_2, ExtendedObject2)