用正则表达式打造免费代理IP池

爬虫的过程中，当对方服务器发现你屡次爬取它，可能会遇到被封IP的苦痛，这时IP就应该换啦，打造IP池的意义十分重要，提供免费IP网站有很多，本次用的是西刺代理IP

# -*- coding: utf-8 -*-
"""
Created on Fri May 11 09:02:12 2018@author: JJ
"""
import urllib.request
import re
def get_proxy(n):url = 'http://www.xicidaili.com/nn/{}'.format(n)headers = ('User-Agent','Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36')opener = urllib.request.build_opener()opener.addheaders = [headers]urllib.request.install_opener(opener)html = opener.open(url).read().decode('utf8')ip_port_list = re.findall(r'<tr class(.*?)</tr>',html,re.S)proxy_list = []for i in ip_port_list:ip = re.findall(r'\d+\.\d+\.\d+\.\d+',i)[0]port = re.findall(r'<td>(\d+)</td>',i)[0]proxy = '{}:{}'.format(ip,port)proxy_list.append(proxy)print(proxy_list)if __name__=='__main__':get_proxy(1)

这段代码是爬取第一页，仅仅做个示范，大家可以在下面写个for循环，多爬几页也是可以的，来看看输出结果：

接下来来看看刚才做的IP池能不能用，或者说效率怎么样。测试网站http://httpbin.org/ip，话不多说上代码：

# -*- coding: utf-8 -*-
"""
Created on Fri May 11 09:02:12 2018@author: JJ
"""
import urllib.request
import re
import time
import random
def get_proxy(n):url = 'http://www.xicidaili.com/nn/{}'.format(n)headers = ('User-Agent','Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36')opener = urllib.request.build_opener()opener.addheaders = [headers]urllib.request.install_opener(opener)html = opener.open(url).read().decode('utf8')ip_port_list = re.findall(r'<tr class(.*?)</tr>',html,re.S)proxy_list = []for i in ip_port_list:ip = re.findall(r'\d+\.\d+\.\d+\.\d+',i)[0]port = re.findall(r'<td>(\d+)</td>',i)[0]proxy = '{}:{}'.format(ip,port)proxy_list.append(proxy)return proxy_listdef proxy_read(proxy_list,i):proxy = proxy_list[i]print('当前IP为:{}'.format(proxy))sleep_time = random.randint(1,3)print('等待{}秒'.format(sleep_time))time.sleep(sleep_time)print('开始测试')proxy_jj = urllib.request.ProxyHandler({'http':proxy})opener = urllib.reequest.build_opener(proxy_jj,urllib.request.HTTPHandler)urllib.request.install_opener(opener)try:html = urllib.request.urlopen('http://httpbin.org/ip')rhtml = html.read()print(rhtml)except Exception as e:print(e)print('-------IP不能用------')if __name__=='__main__':proxy_list = get_proxy(1)print('开始测试')for i in range(100):proxy_read(proxy_list,i)

结果如上图，总得来说，代码很简单，好啦，end啦，下一篇文章‘用xpath打造免费IP池‘。敬请期待