scrapy 使用动态ip代理

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在 middlewares.py 中 更换

https://www.zhihu.com/question/387550141

https://zhuanlan.zhihu.com/p/77172092

class ProxiesMiddleware:
    ALL_EXCEPTIONS = (defer.TimeoutError, TimeoutError, DNSLookupError,
                      ConnectionRefusedError, ConnectionDone, ConnectError,
                      ConnectionLost, TCPTimedOutError, ResponseFailed,
                      IOError, TunnelError)

    def __init__(self):
        self.proxy = redom_proxy()
        self.count = 0
        self.information = self.information_func()

    def information_func(self):
        """
        用于计算每隔多久对代理进行更换方法
        具体方法 获取更换节点时间   当前时间+7000秒+随机一个50到200之间的一个整数  为未来更换代理的时间
        """
        return time.time() + 7000 + random.randint(50, 200)

    def agentExecutable(self, name):
        """每个请求都会经过这里来重复缺点是否到达该更换代理的时间"""
        if time.time() > self.information:
            self.proxy = redom_proxy(spiderhost=name)
            self.information = self.information_func()

    def process_request(self, request, spider):
        source = request.meta.get("source")  # 这是spider中传过来的来确定是哪个源的爬虫
        if self.count % 10000 == 0 and self.count != 0:
            spider.logger.info("[一万个请求啦换代理了]")
            self.proxy = redom_proxy(spiderhost=source)
        self.count += 1
        self.agentExecutable(source)  # 用来判断是否需要更换代理
        spider.logger.info("[request url]   {}".format(request.url))
        spider.logger.info("[proxy]   {}".format(self.proxy))
        request.meta["proxy"] = self.proxy

    def process_response(self, request, response, spider):
        if len(response.text) < 3000 or response.status in [403, 400, 405, 301, 302]:
            source = request.meta.get("source")
            spider.logger.info("[此代理报错]   {}".format(self.proxy))
            new_proxy = redom_proxy(spiderhost=source)
            self.proxy = new_proxy
            spider.logger.info("[更的的新代理为]   {}".format(self.proxy))
            new_request = request.copy()
            new_request_l = new_request.replace(url=request.url)
            return new_request_l
        return response

    def process_exception(self, request, exception, spider):
        # 捕获几乎所有的异常
        if isinstance(exception, self.ALL_EXCEPTIONS):
            # 在日志中打印异常类型
            source = request.meta.get("source")
            spider.logger.info("[Got exception]   {}".format(exception))
            spider.logger.info("[需要更换代理重试]   {}".format(self.proxy))
            new_proxy = redom_proxy(spiderhost=source)
            self.proxy = new_proxy
            spider.logger.info("[更换后的代理为]   {}".format(self.proxy))
            new_request = request.copy()
            new_request_l = new_request.replace(url=request.url)
            return new_request_l
        # 打印出未捕获到的异常
        spider.logger.info("[not contained exception]   {}".format(exception))