python 功能限制包装器（来自https://github.com/themiurgo/ratelim）

Posted 2021-05-10

class patient(object):
    def __init__(self, max_calls, time_interval):
    	if max_calls <= 0:
    	    raise ValueError("max_calls must be positive")
    	if time_interval <= 0:
    	    raise ValueError("time_interval must be positive")
        self.__last_call = None
        self.__time_interval = float(time_interval) / max_calls # seconds

    def __call__(self, f, *args, **kwargs):
        def wrapped_f(*args, **kwargs):
            now = datetime.datetime.now()
            # At the first call, reset the time
            if self.__last_call == None:
                self.__last_call = now
                result = f(*args, **kwargs)
                return result

            time_delta = now - self.__last_call
            time_delta = int(time_delta.total_seconds())
            assert time_delta >= 0
            if time_delta <= self.__time_interval:
                to_sleep = self.__time_interval - time_delta
                # print "To sleep", to_sleep
                time.sleep(to_sleep)

            result = f(*args, **kwargs)
            self.__last_call = datetime.datetime.now()
            return result
        return wrapped_f

    def __numcalls__(self):
        return self.__numcalls