python的爬虫代理设置

现在网站大部分都是反爬虫技术，最简单就是加代理，写了一个代理小程序。

# -*- coding: utf-8 -*-
#__author__ = "雨轩恋i"
#__date__ = "2018年10月30日"

# 导入random模块
import random
# 导入useragent用户代理模块中的UserAgentMiddleware类
from scrapy.downloadermiddlewares.useragent import UserAgentMiddleware

# RotateUserAgentMiddleware类，继承 UserAgentMiddleware 父类
# 作用：创建动态代理列表，随机选取列表中的用户代理头部信息，伪装请求。
#       绑定爬虫程序的每一次请求，一并发送到访问网址。

# 发爬虫技术：由于很多网站设置反爬虫技术，禁止爬虫程序直接访问网页，
#             因此需要创建动态代理，将爬虫程序模拟伪装成浏览器进行网页访问。
class RotateUserAgentMiddleware(UserAgentMiddleware):
    def __init__(self, user_agent=''):
        self.user_agent = user_agent

    def process_request(self, request, spider):
        #这句话用于随机轮换user-agent
        ua = random.choice(self.user_agent_list)
        if ua:
            # 输出自动轮换的user-agent
            print(ua)
            request.headers.setdefault('User-Agent', ua)

    # the default user_agent_list composes chrome,I E,firefox,Mozilla,opera,netscape
    # for more user agent strings,you can find it in http://www.useragentstring.com/pages/useragentstring.php
    # 编写头部请求代理列表
    user_agent_list = [
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1"
        "Mozilla/5.0 (X11; CrOS i686 2268.111.0) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 Safari/536.11",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1092.0 Safari/536.6",
        "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1090.0 Safari/536.6",
        "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/19.77.34.5 Safari/537.1",
        "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.9 Safari/536.5",
        "Mozilla/5.0 (Windows NT 6.0) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.36 Safari/536.5",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
        "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_0) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1062.0 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1062.0 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
        "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.0 Safari/536.3",
        "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/535.24 (KHTML, like Gecko) Chrome/19.0.1055.1 Safari/535.24",
        "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/535.24 (KHTML, like Gecko) Chrome/19.0.1055.1 Safari/535.24"
       ]

可以在自己的爬虫程序中加入这个程序，每次动态的使用代理，将爬虫程序伪装成浏览器，这样就不会被网站禁止了