函数返回值定义#多个返回值 - Tuple#async def function_name(package_name: str) -> Tuple[ParamsPushLvl2Pool, bool]: pass支持传入多类型 - Union#ex: Union[ExpiryT, None] = None,迭代#def _yield_offer_info(_session, from_days_ago: int) -> Iterator[Offer]: