一、

import urllib2

if __name__ == '__main__' :

    url = 'http://www.baidu.com'

    proxy = {'http':'124.235.181.175:80'}

    proxy_support = urllib2.ProxyHandler(proxy)

    opener = urllib2.build_opener(proxy_support)

    opener.addheaders = [('User-Agent','Mozilla/5.0 (Linux; Android 4.0.4; Galaxy Nexus Build/IMM76B) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.133 Mobile Safari/535.19')]

    urllib2.install_opener(opener)    # 用install_opener将配置好的opener安装到全局环境中，这样所有的urllib2.urlopen都会自动使用代理

    response = urllib2.urlopen(url)

    html = response.read().decode('GBK')

    print html

二、

import urllib2

if __name__ == '__main__' :

    url = 'http://www.baidu.com'

    proxy = {'http':'124.235.181.175:80'}

    proxy_handler = urllib2.ProxyHandler(proxy)

    opener = urllib2.build_opener(proxy_handler)

    req = opener.open(url)   # 只有使用opener.open()方法发送请求才使用自定义的代理，而urlopen()则不使用自定义代理

    html = req.read().decode('utf-8')

    print html

三、

import urllib2

import random

if __name__ == '__main__' :

    url = 'http://www.baidu.com/'

    proxy_list = [

        {'http' : '124.88.67.81:80'},

        {'http' : '124.235.181.175:80'},

        {'http' : '123.53.134.254:8010'},

        {'http' : '61.135.217.7:80'},

        {'http' : '116.77.204.2:80'}

        ]

    proxy = random.choice(proxy_list)  # 随机选择一个代理

    proxy_handler = urllib2.ProxyHandler(proxy)  # 使用选择的代理构建代理处理器对象

    opener = urllib2.build_opener(proxy_handler)

    opener.addheaders = [('User-Agent','Mozilla/5.0 (Linux; Android 4.0.4; Galaxy Nexus Build/IMM76B) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.133 Mobile Safari/535.19')]

    urllib2.install_opener(opener)

    req = urllib2.Request(url)

    response = urllib2.urlopen(req)

    html = response.read().decode('utf-8')

    print html