scrapy Middleware

1. scrapy 自建的中间件
2. Referer中间件
3. randomUA中间件
4. proxy中间件

scrapy 自建的中间件

# -*- coding: utf-8 -*-# Define here the models for your spider middleware## See documentation in:# http://doc.scrapy.org/en/latest/topics/spider-middleware.htmlfrom scrapy import signalsclass ItcastSpiderMiddleware(object):    # Not all methods need to be defined. If a method is not defined,    # scrapy acts as if the spider middleware does not modify the    # passed objects.    @classmethod    def from_crawler(cls, crawler):        # This method is used by Scrapy to create your spiders.        s = cls()        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)        return s    def process_spider_input(self, response, spider):        # Called for each response that goes through the spider        # middleware and into the spider.        # Should return None or raise an exception.        return None    def process_spider_output(self, response, result, spider):        # Called with the results returned from the Spider, after        # it has processed the response.        # Must return an iterable of Request, dict or Item objects.        for i in result:            yield i    def process_spider_exception(self, response, exception, spider):        # Called when a spider or process_spider_input() method        # (from other spider middleware) raises an exception.        # Should return either None or an iterable of Response, dict        # or Item objects.        pass    def process_start_requests(self, start_requests, spider):        # Called with the start requests of the spider, and works        # similarly to the process_spider_output() method, except        # that it doesn’t have a response associated.        # Must return only requests (not items).        for r in start_requests:            yield r    def spider_opened(self, spider):        spider.logger.info('Spider opened: %s' % spider.name)

Referer中间件

class Referer(object):    def process_request(self, request, spider):        '''设置headers和切换请求头        :param request: 请求体        :param spider: spider对象        :return: None        '''        referer = request.meta.get('referer', None)        if referer:            request.headers['referer'] = referer

RandomUserAgent

class RandomUserAgent(object):    def process_request(self, request, spider):        # 随机获取一个用户头        ua = random.choice(PY3_UA_LIST)        # 设置用户头        # print (ua)        # print(request.headers)        request.headers['User-Agent'] = ua

# settings.pyPY3_UA_LIST = [    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.19 (KHTML, like Gecko) Chrome/0.2.151.0 Safari/525.19 ",    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.2.149.29 Safari/525.13 ",    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.13(KHTML, like Gecko) Chrome/0.2.149.27 Safari/525.13 ",    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.2.149.27 Safari/525.13 ",    "Opera/7.51 (Windows NT 5.1; U) [en] ",    "Opera/8.0 (Windows NT 5.1; U; en) ",    "Opera/8.0 (Windows NT 5.1; U; zh-cn) ",    "Opera/9.80 (Windows NT 5.1; U; ru) Presto/2.7.39 Version/11.00 ",    "Opera/9.80 (Windows NT 5.1; U; zh-tw) Presto/2.8.131 Version/11.10 ",    "Opera/9.80 (Windows NT 5.1; U; Opera/9.80 (J2ME/MIDP; Opera Mini/5.0.18635/1030; U; en) Presto/2.4.15; ru) Presto/2.8.99 Version/11.10 ",    "Opera/9.80 (J2ME/MIDP; Opera Mini/5.0(Windows; U; Windows NT 5.1; en-US)/23.390; U; en) Presto/2.5.25 Version/10.54 ",    "Opera/9.80 (J2ME/MIDP; Opera Mini/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.2.3) Gecko/23.377; U; en) Presto/2.5.25 Version/10.54 ",    "Opera/9.80 (J2ME/MIDP; Opera Mini/(Windows; U; Windows NT 5.1; en-US) AppleWebKit/23.411; U; en) Presto/2.5.25 Version/10.54 ",    "Opera/9.80 (Windows NT 5.1; Opera Mobi/49; U; en) Presto/2.4.18 Version/10.00 ",]

RandomProxy

class RandomProxy(object):    def process_request(self, request, spider):        # 随机获取一个代理        proxy = random.choice(PY3_PROXY_LIST)        # 判断代理情况        if 'user_passwd' in proxy:            # 对账号进行编码            b64_user_pwd = base64.b64encode(proxy['user_passwd'].encode())            # 代理权限认证            request.headers['Proxy-Authorization'] = 'Basic ' + b64_user_pwd.decode()            # 设置代理            request.meta['proxy'] = proxy['ip_port']        else:            request.meta['proxy'] = proxy['ip_port']

# settings.pyPY3_PROXY_LIST = [    {"ip_port": "116.62.112.142:16816", "user_passwd": "morganna_mode_g:ggc22qxp"},    {"ip_port": "119.23.63.152:8118"},]