"""`Chained Factories` pattern.""" from dependency_injector import containers, providers class SqlAlchemyDatabaseService: def __init__(self, session, base_class): self.session = session self.base_class = base_class class TokensService: def __init__(self, id_generator, database): self.id_generator = id_generator self.database = database class Token: ... class UsersService: def __init__(self, id_generator, database): self.id_generator = id_generator self.database = database class User: ... # Sample objects session = object() id_generator = object() class Container(containers.DeclarativeContainer): database = providers.Factory( SqlAlchemyDatabaseService, session=session, ) token_service = providers.Factory( TokensService, id_generator=id_generator, database=providers.Factory( database, base_class=Token, ), ) user_service = providers.Factory( UsersService, id_generator=id_generator, database=providers.Factory( database, base_class=User, ), ) if __name__ == "__main__": container = Container() token_service = container.token_service() assert token_service.database.base_class is Token user_service = container.user_service() assert user_service.database.base_class is User