Throttles a function for N number of seconds between calls

throttle_decorator.py

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# The MIT License (MIT)
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# Copyright (c) 2015 Mark LaPerriere
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class throttle(object):
    """Throttles a function for N number of seconds between calls
        Note: Not compatible with class methods but could be ported to do so

    :Parameters:
        interval_sec : int | float
            The number of seconds to enforce between each call
        blocking : bool
            Whether or not to insert a sleep between calls otherwise raise an exception
            [default: True]

    :IVariables:
        _init : bool
            Determines if this is the first call to the function
        interval : float
            Stores the number of seconds to enforce between each call
        blocking : bool
            Block the current call to ensure the interval is kept, otherwise raise an exception
            if the time between calls was too short
        last_call : float
            Keeps track of the last time the wrapped function was called
    """

    def __init__(self, interval_sec, blocking=True):
        self._init = True
        self.blocking = bool(blocking)
        self.last_call = time.time()
        self.interval = float(interval_sec)

    def __call__(self, func):

        @wraps(func)
        def wrapper(*args, **kwargs):
            if self._init:
                self._init = False
            else:
                last_call_delta = time.time() - self.last_call
                if last_call_delta < self.interval:
                    logger.debug(
                        'Interval {0:f} must be > {1:f}'.format(last_call_delta, self.interval))
                    if self.blocking:
                        sleep_sec = self.interval - last_call_delta
                        logger.debug('Blocking for {0}'.format(sleep_sec))
                        time.sleep(sleep_sec)
                    else:
                        raise Exception(
                            'Interval {0:f} must be > {1:f}'.format(last_call_delta, self.interval))

            result = func(*args, **kwargs)

            self.last_call = time.time()

            return result
        return wrapper