requests+正则表达式爬取ip

 #requests+正则表达式爬取ip
 #findall方法，如果表达式中包含有子组，则会把子组单独返回出来，如果有多个子组，则会组合成元祖
 import requests
 import re
 def get_ip(url):
     headers={'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.75 Safari/537.36 LBBROWSER'}
     response = requests.get(url,headers=headers)
     pattern= re.compile(r'(?:(?:[0-1]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])\.){3}(?:[0-1]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]).*\s*.*(?:\d+)')
     result = re.findall(pattern,response.text)
     #print(result)
     return result

 def make_iplist(iplist,result):

     for ip in result:
         ip = re.sub(r'</td>\s*.*<td>',':',ip)
         iplist.append(ip)
     return iplist

 def main(num):

     iplist = []
     for i in range(1,num):
         url = 'http://www.xicidaili.com/nt/'
         url =url + str(num)
         #print(url)
         result = get_ip(url)
         iplist = make_iplist(iplist,result)

     for j in iplist:
         print(j)
 if __name__ == '__main__':
     num=int(input('请输入要抓取的页数：'))
     main(num)