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
