from dependency_injector import containers, providers class ApiClient: def __init__(self, api_key: str, timeout: int): self.api_key = api_key self.timeout = timeout class Service: def __init__(self, api_client: ApiClient): self.api_client = api_client class Container(containers.DeclarativeContainer): config = providers.Configuration() api_client = providers.Singleton( ApiClient, api_key=config.api_key, timeout=config.timeout.as_int(), ) service = providers.Factory( Service, api_client=api_client, ) if __name__ == '__main__': container = Container() container.config.api_key.from_env('API_KEY') container.config.timeout.from_env('TIMEOUT') service = container.service()