python爬虫挂代理

以下是GET的方法，使用的代理接口网站是 http://www.xicidaili.com/nn/

#-*- coding:utf-8 -*-
from bs4 import BeautifulSoup
import requests,chardet,urllib2

ip_list=[]
def get_ip_list(url, headers):
    web_data = requests.get(url, headers=headers)
    soup = BeautifulSoup(web_data.text, 'lxml')
    ips = soup.find_all('tr')
    ip_list = []
    for i in range(1, len(ips)):
        ip_info = ips[i]
        tds = ip_info.find_all('td')
        ip_list.append('http://' + tds[1].text + ':' + tds[2].text)
    return ip_list

def get_random_ip(ip_list):
    proxies = {'http': ip_list[0]}
    return proxies

def getip():
    global ip_list
    url = 'http://www.xicidaili.com/nn/'
    headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36'}
    if not ip_list:
        ip_list = get_ip_list(url, headers=headers)
    print ip_list
    proxies = get_random_ip(ip_list)
    return proxies

def deleteip():
    global ip_list
    ip_list.pop(0)

def urllink(link):  # 网页HTML获取以及编码转换
    for i in range(12) :
        try:
            ip = getip()
            print ip
            proxy_support = urllib2.ProxyHandler(ip)
            opener = urllib2.build_opener(proxy_support)
            urllib2.install_opener(opener)
            html_1 = urllib2.urlopen(link, timeout=10).read()
            break
        except Exception,e:
            deleteip()
            print '错误',i,e
            pass
    if i==11:
        return ''
    encoding_dict = chardet.detect(html_1)
    web_encoding = encoding_dict['encoding']
    if web_encoding == 'utf-8' or web_encoding == 'UTF-8':
        html = html_1
    else:
        html = html_1.decode('gbk', 'ignore').encode('utf-8')
    return html

print urllink("http://ccdas.ipmph.com/pc/clinicalExam/getClinicalExamDetail?articleId=8165")