rateLimitDecorator.py

import time


def rate_limited(max_rate):
    """
    max_rate is in seconds
    """
    min_interval = 1.0 / float(max_rate)

    def decorate(func):
        last_time_called = [0.0]

        def rate_limited_function(*args, **kargs):
            elapsed = time.clock() - last_time_called[0]
            left_to_wait = min_interval - elapsed

            if left_to_wait > 0:
                time.sleep(left_to_wait)

            ret = func(*args, **kargs)
            last_time_called[0] = time.clock()
            return ret
        return rate_limited_function
    return decorate


@rate_limited(5)
def print_number(num):
    print num


if __name__ == "__main__":
    print "This should print 1,2,3... at about 2 per second."
    for i in range(1, 100):
        print_number(i)

http://blog.gregburek.com/2011/12/05/Rate-limiting-with-decorators/