Python2 基于urllib2 的HTTP请求类

一个利用urllib2模块编写的下载器，虽然有了requests模块，但是毕竟标准库
 1 import urllib2,random
 2 
 3 class strong_down():
 4     def __init__(self):
 5        #ip_list和agent_list可以自己写到config文件中，然后读出来
　　　　　　self.proxy_ip_list = ['122.224.227.202:3128',
 6                               '182.254.220.21:3128',
 7                               '123.7.115.141:9797',
 8                               '183.61.236.54:3128',
 9                               '124.88.67.31:843',
10                               '120.24.73.165:3128']
11         self.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",
12                                 "Mozilla/5.0 (X11; CrOS i686 2268.111.0) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 Safari/536.11"
13                                 ]
14         self.proxy_ip_num = len(self.proxy_ip_list)
15         self.user_agent_num = len(self.user_agent_list)
16 
17     def proxy_down(self,url,time_out=5,num_retries=3):
18         proxy_ip = self.proxy_ip_list[random.randint(0,self.proxy_ip_num-1)]
19         user_agent = self.user_agent_list[random.randint(0,self.user_agent_num-1)]
20         proxy_handler = urllib2.ProxyHandler({'http':proxy_ip})
21         opener = urllib2.build_opener(proxy_handler)
22         request = urllib2.Request(url,headers={'User-Agent':user_agent})
23         #print request.headers
24         try:
25             response = opener.open(request,timeout=time_out)
26             html = response.read()
27             if html == None:print 'none'
28             return  html
29         except urllib2.URLError, e:
30             if hasattr(e,"code"):
31                 print '0',e.code,e.reason
32             if hasattr(e,"reason"):
33                 print '1',e.reason
34             if num_retries>1:
35                 return self.proxy_down(url,time_out,num_retries-1)
36         except Exception as e:
37             print 'error:',e
38             if num_retries>0:
39                 print 'proxy try...'
40                 return self.proxy_down(url,time_out,num_retries-1)
41             else:
42                 print u'代理也没diao用'
43                 return  None
44 
45 
46 
47     def down(self,url,time_out=5,num_retries=3):
48         user_agent = self.user_agent_list[random.randint(0,self.user_agent_num-1)]
49         request = urllib2.Request(url,headers={'User-Agent':user_agent})
50         try:
51             response = urllib2.urlopen(request,timeout=time_out)
52             html = response.read()
53             return html
54         except urllib2.URLError, e:
55             if hasattr(e,"code"):
56                 print '0', e.code,e.reason,e.msg
57             if hasattr(e,"reason"):
58                 print '1', e.reason
59             if num_retries>0:
60                 print 'try...'
61                 return self.down(url,time_out,num_retries-1)
62         except Exception as e:
63             print 'error:',e
64             if num_retries>0:
65                 print 'try...'
66                 return self.down(url,time_out,num_retries-1)
67 
68             #代理
69             if num_retries <=0:
70                 return self.proxy_down(url,time_out,num_retries=3)