"""`Configuration` provider strict mode example.""" from dependency_injector import containers, providers, errors class ApiClient: def __init__(self, api_key: str, timeout: int): self.api_key = api_key self.timeout = timeout class Container(containers.DeclarativeContainer): config = providers.Configuration(strict=True) api_client_factory = providers.Factory( ApiClient, api_key=config.api.key, timeout=config.api.timeout.as_int(), ) if __name__ == '__main__': container = Container() try: api_client = container.api_client_factory() except errors.Error: # raises error: Undefined configuration option "config.api.key" ...