如何使用装饰器对 Python 2.7 中的函数进行速率限制？

Question

我正在尝试在 Python 中编写一个装饰器来限制函数在一段时间内被调用的次数。我预计会这样使用它：

@ratelimit(seconds=15)
def foo():
    print 'hello'

start = time.time()
while time.time() - start < 10:
    foo()

> 'hello'
> 'hello'

所以装饰函数最多可以在seconds调用一次。在实施方面我有这个，但它不起作用，因为我不确定在后续调用之间保持 last_call 的正确方法：

import time

def ratelimit(seconds=10):

    last_call = None # Never call decorated function
    def decorator(func):


        def wrapper(*args, **kwargs):

            if last_call is None or time.time() - last_call > seconds:
                result = func(*args, **kwargs)
                last_call = time.time()
                return result

            return wraps(func)(wrapper)

    return decorator

Answer 1

下面的代码在 python 2.7 中对我来说工作正常。

import time
from functools import wraps

last_called = dict()  # When last called, and with what result

def ratelimit(seconds=10, timer=time.time):
    def decorator(func):
        last_called[func] = None

        @wraps(func)
        def wrapper(*args, **kwargs):
            now = timer()
            call_data = last_called.get(func, None)
            if call_data is None or now - call_data[0] >= seconds:
                result = func(*args, **kwargs)
                last_called[func] = (now, result)
            else:
                result = call_data[1]  # Replay rate-limited result
            return result
        return wrapper
    return decorator

如何使用装饰器对 Python 2.7 中的函数进行速率限制？

How can I rate limit a function in Python 2.7 with a decorator?

python

decorator

rate-limiting