Python：如何使用龍捲風從發電機功能返回？

我用產量和任務來獲得異步4個jsons：Python：如何使用龍捲風從發電機功能返回？

@gen.engine 
def get_user_data(self, sn, snid, fast_withdrawals): 
    end_timestamp = time.time() 
    start_timestamp = end_timestamp - CONFIG.LOYALITY_LEVELS.PERIOD 

    active_apps_response, total_payments_response, payments_for_period_response, withdrawals_response = yield [ 
     gen.Task(self.http_client.fetch, self.__get_active_apps_url(sn, snid)), gen.Task(self.http_client.fetch, self.__get_total_payments_url(sn, snid)), 
     gen.Task(self.http_client.fetch, self.__get_payments_sum_for_period_url(sn, snid, start_timestamp, end_timestamp)), 
     gen.Task(self.http_client.fetch, self.__get_total_withdrawals_url(sn, snid, fast_withdrawals)) 
    ] 

    active_apps = self.__active_apps_handler(active_apps_response) 
    total_payments = self.__get_total_payments_handler(total_payments_response) 
    payments_for_period = self.__payments_sum_for_period_handler(payments_for_period_response) 
    withdrawals = self.__get_total_withdrawals_handler(withdrawals_response) 

    yield gen.Return(active_apps, total_payments, payments_for_period, withdrawals)

但是，如果我用產量，而不是返回上層函數成爲生成器也是一樣，我不能太使用的回報。那麼，如何在沒有調用函數發生器的情況下返回龍捲風函數的結果呢？我正在使用Python 2.7

來源

2013-05-27 Robotex

您不能同時返回值和產出值。當你產生值時，函數返回一個生成器 - 所以它已經返回一個值，不能返回更多。這樣做根本沒有意義。

您可以調用return而沒有任何值導致StopIteration異常並結束生成器，但返回值在生成器中從語義上講沒有意義。

如果你想有時返回一個生成器，有時返回一個值，用另一個返回一個生成器（通過調用這個函數創建的）或替代值來包裝你的函數，儘管我不會這麼做從設計的角度來看，這通常是一個壞主意。

來源

2013-05-27 15:35:18

也許你可以這樣寫：

@gen.coroutine 
def get_user_data(self, sn, snid, fast_withdrawals): 
    end_timestamp = time.time() 
    start_timestamp = end_timestamp - CONFIG.LOYALITY_LEVELS.PERIOD 

    active_apps_response, total_payments_response, payments_for_period_response, withdrawals_response = yield [ 
    self.http_client.fetch(self.__get_active_apps_url(sn, snid)), 
    self.http_client.fetch(self.__get_total_payments_url(sn, snid)), 
    self.http_client.fetch(self.__get_payments_sum_for_period_url(sn, snid, start_timestamp, end_timestamp)), 
    self.http_client.fetch(self.__get_total_withdrawals_url(sn, snid, fast_withdrawals)) 
] 

active_apps = self.__active_apps_handler(active_apps_response) 
total_payments = self.__get_total_payments_handler(total_payments_response) 
payments_for_period = self.__payments_sum_for_period_handler(payments_for_period_response) 
withdrawals = self.__get_total_withdrawals_handler(withdrawals_response) 

raise gen.Return(active_apps, total_payments, payments_for_period, withdrawals)

發動機是舊的接口;更多關於這個你可以看到龍捲風3.0文檔。

來源

2013-05-28 22:15:42 cloudaice

Python：如何使用龍捲風從發電機功能返回？

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