爬虫(2)--- 构建简单代理IP池


目录

1. 何为代理IP池?
2. 代理IP池构建
  2.1 浏览器伪装
  2.2 代理IP爬取
  2.3 代理IP验证
  2.4 代理IP多进程验证
  2.5 函数调用
3. 后记


1 何为代理IP池?

在写爬虫爬取数据的时候总会遇到各种各样的反爬技术,而利用高匿代理IP是防止被墙方法之一,所以在大型爬虫中不得不考虑代理IP池的构建。
  在上次爬取拉勾网信息的时候采用了西刺免费代理IP的API构建代理IP池,今天发现打不开该地址,故重新编写代理IP池的构建,依旧是依赖西刺的代理IP资源。本次主要整理Python并发知识并爬取国内高匿代理

2 简单代理IP池构建

  • 浏览器伪装
  • 代理IP爬取
  • 代理IP验证
  • 代理IP多进程验证
  • 函数调用

2.1 浏览器伪装

import urllib.request  
import urllib.parse 
import time  
from multiprocessing import Pool#多进程
import random
from lxml import etree  #解析
def GetUserAgent():
    '''
    功能:随机获取HTTP_User_Agent
    '''
    user_agents=[
    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AcooBrowser; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
    "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Acoo Browser; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.0.04506)",
    "Mozilla/4.0 (compatible; MSIE 7.0; AOL 9.5; AOLBuild 4337.35; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
    "Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)",
    "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 2.0.50727; Media Center PC 6.0)",
    "Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.0.3705; .NET CLR 1.1.4322)",
    "Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.2; .NET CLR 3.0.04506.30)",
    "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN) AppleWebKit/523.15 (KHTML, like Gecko, Safari/419.3) Arora/0.3 (Change: 287 c9dfb30)",
    "Mozilla/5.0 (X11; U; Linux; en-US) AppleWebKit/527+ (KHTML, like Gecko, Safari/419.3) Arora/0.6",
    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.2pre) Gecko/20070215 K-Ninja/2.1.1",
    "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9) Gecko/20080705 Firefox/3.0 Kapiko/3.0",
    "Mozilla/5.0 (X11; Linux i686; U;) Gecko/20070322 Kazehakase/0.4.5",
    "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.8) Gecko Fedora/1.9.0.8-1.fc10 Kazehakase/0.5.6",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11",
    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/535.20 (KHTML, like Gecko) Chrome/19.0.1036.7 Safari/535.20",
    "Opera/9.80 (Macintosh; Intel Mac OS X 10.6.8; U; fr) Presto/2.9.168 Version/11.52",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.11 TaoBrowser/2.0 Safari/536.11",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.71 Safari/537.1 LBBROWSER",
    "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; LBBROWSER)",
    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; QQDownload 732; .NET4.0C; .NET4.0E; LBBROWSER)",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.84 Safari/535.11 LBBROWSER",
    "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)",
    "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; QQBrowser/7.0.3698.400)",
    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; QQDownload 732; .NET4.0C; .NET4.0E)",
    "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; SV1; QQDownload 732; .NET4.0C; .NET4.0E; 360SE)",
    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; QQDownload 732; .NET4.0C; .NET4.0E)",
    "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)",
    "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1",
    "Mozilla/5.0 (iPad; U; CPU OS 4_2_1 like Mac OS X; zh-cn) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5",
    "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:2.0b13pre) Gecko/20110307 Firefox/4.0b13pre",
    "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/20100101 Firefox/16.0",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11",
    "Mozilla/5.0 (X11; U; Linux x86_64; zh-CN; rv:1.9.2.10) Gecko/20100922 Ubuntu/10.10 (maverick) Firefox/3.6.10"
    ]
    user_agent = random.choice(user_agents)
    return user_agent

2.2 代理IP爬取

本次爬取是基于西刺国内高匿代理,利用xpath表达式进行解析。

def getProxies():
    '''
    功能:爬取西刺高匿IP构造原始代理IP池
    '''
    init_proxies = []
    ##爬取前十页
    for i in range(1,11):
        print("####")
        print("####爬取第"+str(i)+"页####")
        print("####")        
        print("IP地址\t\t\t端口\t存活时间\t\t验证时间")
        url = "http://www.xicidaili.com/nn/"+str(i)
        user_agent = GetUserAgent()
        headers=("User-Agent",user_agent)
        opener = urllib.request.build_opener() 
        opener.addheaders = [headers] 
        try:
            data = opener.open(url,timeout=5).read()
        except Exception as er:
            print("爬取的时候发生错误,具体如下:")
            print(er)
        selector=etree.HTML(data) 
        ip_addrs = selector.xpath('//tr[@class="odd"]/td[2]/text()')  #IP地址
        port = selector.xpath('//tr[@class="odd"]/td[3]/text()')  #端口
        sur_time = selector.xpath('//tr[@class="odd"]/td[9]/text()')  #存活时间
        ver_time = selector.xpath('//tr[@class="odd"]/td[10]/text()')  #验证时间
        for j in range(len(ip_addrs)):
            ip = ip_addrs[j]+":"+port[j] 
            init_proxies.append(ip)
            #输出爬取数据 
            print(ip_addrs[j]+"\t\t"+port[j]+"\t\t"+sur_time[j]+"\t"+ver_time[j])
    return init_proxies

2.3 代理IP验证

利用百度首页进行IP有效性验证,设置超时时间为5秒,睡眠时间为2秒。

def testProxy(curr_ip):
    '''
    功能:验证IP有效性
    @curr_ip:当前被验证的IP
    '''
    tmp_proxies = []
    #socket.setdefaulttimeout(10)  #设置全局超时时间
    tarURL = "http://www.baidu.com/" 
    user_agent = GetUserAgent()
    proxy_support = urllib.request.ProxyHandler({"http":curr_ip})
    opener = urllib.request.build_opener(proxy_support)
    opener.addheaders=[("User-Agent",user_agent)]
    urllib.request.install_opener(opener)
    try:
        res = urllib.request.urlopen(tarURL,timeout=5).read()
        if len(res)!=0:
            tmp_proxies.append(curr_ip)
    except urllib.error.URLError as er2: 
        if hasattr(er2,"code"):
            print("验证代理IP("+curr_ip+")时发生错误(错误代码):"+str(er2.code))
        if hasattr(er2,"reason"):
            print("验证代理IP("+curr_ip+")时发生错误(错误原因):"+str(er2.reason))
    except Exception as er:
        print("验证代理IP("+curr_ip+")时发生如下错误):")
        print(er)
    time.sleep(2)
    return tmp_proxies 

2.4 代理IP多线程验证

def mulTestProxies(init_proxies):
    '''
    功能:多进程验证IP有效性
    @init_proxies:原始未验证代理IP池
    '''
    pool = Pool(processes=7)
    fl_proxies = pool.map(testProxy,init_proxies)
    pool.close()
    pool.join()  #等待进程池中的worker进程执行完毕
    return fl_proxies

2.5 函数调用

if __name__ == '__main__':
    #---(1)获取代理IP池
    init_proxies = getProxies()  #获取原始代理IP
    tmp_proxies = mulTestProxies(init_proxies) #多进程测试原始代理IP  
    proxy_addrs = []
    for tmp_proxy in tmp_proxies:
        if len(tmp_proxy)!=0:
            proxy_addrs.append(tmp_proxy)

本次共爬取了500个高匿IP,只有32个通过验证,代理IP的质量也是较为一般的。

3 后记

在此只是简单构建了代理IP池,完整的代理IP池的构建还需多方IP来源、存储、定时更新等功能,在后面的学习中将进一步加强代理IP池的构建。

参考与拓展阅读:
[1]python开源IP代理池--IPProxys
[2]简单爬虫代理IP池


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