API 制限をかけるクラス（デコレータつき。）

apilimit.py

# coding: utf8
from __future__ import unicode_literals, print_function, division
from functools import wraps
import redis
import time


class APILimit(object):

    class APILimitExceed(Exception):
        pass

    def __init__(self, redis, max_calls, in_seconds, key_prefix=b''):
        self.max_calls = max_calls
        self.in_seconds = in_seconds
        self.redis = redis
        self.key_prefix = key_prefix

    def call(self, key):
        r = self.redis
        c = r.llen(key)
        if c is not None and c > self.max_calls:
            return False
        if r.exists(key):
            r.rpushx(key, b'')
        else:
            with r.pipeline() as p:
                p.multi()
                p.rpush(key, b'')
                p.expire(key, self.in_seconds)
                p.execute()
        return True

    @classmethod
    def decorate(
        cls, redis_, key=(lambda x, *args, **kwargs: x), *args, **kwargs
    ):
        limiter = APILimit(redis_, *args, **kwargs)

        def wrapper(f):
            @wraps(f)
            def wrapped(*args, **kwargs):
                if limiter.call(key(*args, **kwargs)):
                    return f(*args, **kwargs)
                else:
                    raise APILimit.APILimitExceed
            return wrapped
        return wrapper