限制限制GRequests中HTTP请求的速率

因为我不得不自己解决这个问题，所以要回答我自己的问题，并且关于此问题的信息似乎很少。

这个想法如下。与GRequests一起使用的每个请求对象在创建时都可以将会话对象作为参数。另一方面，会话对象可以安装在发出请求时使用的HTTP适配器。通过创建我们自己的适配器，我们可以拦截请求并对请求进行速率限制，从而找到最适合我们的应用程序的方式。就我而言，我得到了下面的代码。

用于限制的对象：

DEFAULT_BURST_WINDOW = datetime.timedelta(seconds=5)DEFAULT_WAIT_WINDOW = datetime.timedelta(seconds=15)class BurstThrottle(object):    max_hits = None    hits = None    burst_window = None    total_window = None    timestamp = None    def __init__(self, max_hits, burst_window, wait_window):        self.max_hits = max_hits        self.hits = 0        self.burst_window = burst_window        self.total_window = burst_window + wait_window        self.timestamp = datetime.datetime.min    def throttle(self):        now = datetime.datetime.utcnow()        if now < self.timestamp + self.total_window: if (now < self.timestamp + self.burst_window) and (self.hits < self.max_hits):     self.hits += 1     return datetime.timedelta(0) else:     return self.timestamp + self.total_window - now        else: self.timestamp = now self.hits = 1 return datetime.timedelta(0)

HTTP适配器：

class MyHttpAdapter(requests.adapters.HTTPAdapter):    throttle = None    def __init__(self, pool_connections=requests.adapters.DEFAULT_POOLSIZE,      pool_maxsize=requests.adapters.DEFAULT_POOLSIZE, max_retries=requests.adapters.DEFAULT_RETRIES,      pool_block=requests.adapters.DEFAULT_POOLBLOCK, burst_window=DEFAULT_BURST_WINDOW,      wait_window=DEFAULT_WAIT_WINDOW):        self.throttle = BurstThrottle(pool_maxsize, burst_window, wait_window)        super(MyHttpAdapter, self).__init__(pool_connections=pool_connections, pool_maxsize=pool_maxsize,max_retries=max_retries, pool_block=pool_block)    def send(self, request, stream=False, timeout=None, verify=True, cert=None, proxies=None):        request_successful = False        response = None        while not request_successful: wait_time = self.throttle.throttle() while wait_time > datetime.timedelta(0):     gevent.sleep(wait_time.total_seconds(), ref=True)     wait_time = self.throttle.throttle() response = super(MyHttpAdapter, self).send(request, stream=stream, timeout=timeout,verify=verify, cert=cert, proxies=proxies) if response.status_pre != 429:     request_successful = True        return response

设定：

requests_adapter = adapter.MyHttpAdapter(    pool_connections=__CONCURRENT_LIMIT__,    pool_maxsize=__CONCURRENT_LIMIT__,    max_retries=0,    pool_block=False,    burst_window=datetime.timedelta(seconds=5),    wait_window=datetime.timedelta(seconds=20))requests_session = requests.session()requests_session.mount('http://', requests_adapter)requests_session.mount('https://', requests_adapter)unsent_requests = (grequests.get(url,hooks={'response': handle_response},session=requests_session) for url in urls)grequests.map(unsent_requests, size=__CONCURRENT_LIMIT__)