爬蟲代理ip使用方法，python：從零開始教你建立爬蟲代理ip池

一、為什么需要建立爬蟲代理ip池

          在眾多的網站防爬措施中，有一種是根據ip的訪問頻率進行限制的，在某段時間內，當某個ip的訪問量達到一定的閥值時，該ip會被拉黑、在一段時間內被禁止訪問。這種時候，可以通過降低爬蟲的頻率，或者更改ip來應對。后者就需要有一個可用的代理ip池，以供爬蟲工作時切換。

二、如何建立一個爬蟲代理ip池

 思路：   1、找到一個免費的ip代理網站(如：西刺代理)2、爬取ip（常規爬取requests+BeautifulSoup）3、驗證ip有效性（攜帶爬取到的ip，去訪問指定的url，看返回的狀態碼是不是200）4、記錄ip （寫到文檔）代碼如下：

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import requests,threading,datetime
from bs4 import BeautifulSoup
import random"""
1、抓取西刺代理網站的代理ip
2、并根據指定的目標url,對抓取到ip的有效性進行驗證
3、最后存到指定的path
"""# ------------------------------------------------------文檔處理--------------------------------------------------------
# 寫入文檔
def write(path,text):with open(path,'a', encoding='utf-8') as f:f.writelines(text)f.write('\n')
# 清空文檔
def truncatefile(path):with open(path, 'w', encoding='utf-8') as f:f.truncate()
# 讀取文檔
def read(path):with open(path, 'r', encoding='utf-8') as f:txt = []for s in f.readlines():txt.append(s.strip())return txt
# ----------------------------------------------------------------------------------------------------------------------
# 計算時間差,格式: 時分秒
def gettimediff(start,end):seconds = (end - start).secondsm, s = divmod(seconds, 60)h, m = divmod(m, 60)diff = ("%02d:%02d:%02d" % (h, m, s))return diff
# ----------------------------------------------------------------------------------------------------------------------
# 返回一個隨機的請求頭 headers
def getheaders():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"]UserAgent=random.choice(user_agent_list)headers = {'User-Agent': UserAgent}return headers
# -----------------------------------------------------檢查ip是否可用----------------------------------------------------
def checkip(targeturl,ip):headers =getheaders()  # 定制請求頭proxies = {"http": "http://"+ip, "https": "http://"+ip}  # 代理iptry:response=requests.get(url=targeturl,proxies=proxies,headers=headers,timeout=5).status_codeif response == 200 :return Trueelse:return Falseexcept:return False#-------------------------------------------------------獲取代理方法----------------------------------------------------
# 免費代理 XiciDaili
def findip(type,pagenum,targeturl,path): # ip類型,頁碼,目標url,存放ip的路徑list={'1': 'http://www.xicidaili.com/nt/', # xicidaili國內普通代理'2': 'http://www.xicidaili.com/nn/', # xicidaili國內高匿代理'3': 'http://www.xicidaili.com/wn/', # xicidaili國內https代理'4': 'http://www.xicidaili.com/wt/'} # xicidaili國外http代理url=list[str(type)]+str(pagenum) # 配置urlheaders = getheaders() # 定制請求頭html=requests.get(url=url,headers=headers,timeout = 5).textsoup=BeautifulSoup(html,'lxml')all=soup.find_all('tr',class_='odd')for i in all:t=i.find_all('td')ip=t[1].text+':'+t[2].textis_avail = checkip(targeturl,ip)if is_avail == True:write(path=path,text=ip)print(ip)#-----------------------------------------------------多線程抓取ip入口---------------------------------------------------
def getip(targeturl,path):truncatefile(path) # 爬取前清空文檔start = datetime.datetime.now() # 開始時間threads=[]for type in range(4):   # 四種類型ip,每種類型取前三頁,共12條線程for pagenum in range(3):t=threading.Thread(target=findip,args=(type+1,pagenum+1,targeturl,path))threads.append(t)print('開始爬取代理ip')for s in threads: # 開啟多線程爬取s.start()for e in threads: # 等待所有線程結束e.join()print('爬取完成')end = datetime.datetime.now() # 結束時間diff = gettimediff(start, end)  # 計算耗時ips = read(path)  # 讀取爬到的ip數量print('一共爬取代理ip: %s 個,共耗時: %s \n' % (len(ips), diff))#-------------------------------------------------------啟動-----------------------------------------------------------
if __name__ == '__main__':path = 'ip.txt' # 存放爬取ip的文檔pathtargeturl = 'http://www.cnblogs.com/TurboWay/' # 驗證ip有效性的指定urlgetip(targeturl,path)

爬蟲代理ip使用方法。結果：