基于python第三方requests 模块的HTTP请求类

 1 class StrongDownload(object):
 2     
 3     def __init__(self):
 4         #拿到代理iplist
 5         self.iplist = [‘自己想办法搞‘] #
 6         self.UserAgent = [‘自己想办法搞‘]  
 7     
 8     def get(self,url,timeout,proxy=False,num_retries=3):
 9         ‘‘‘url timeout,proxy,num_retries
10                 返回response对象
11         ‘‘‘
12         #伪造UserAgent
13         UA = self.UserAgent[random.randint(0,len(self.UserAgent)-1)]
14         #UA = random.choice(self.UserAgent)
15         headers = {‘User-Agent‘:UA}
16         if proxy == False:
17             try:
18                 return requests.get(url,timeout=timeout,headers=headers)
19             except Exception as e:
20                 print e
21                 #判断retries
22                 if num_retries>0:
23                     print u‘爬取网页错误,10s后继续尝试.....‘
24                     time.sleep(1)
25                     return self.get(url, timeout, False, num_retries-1)
26                 else:#重试次数用尽,使用代理
27                     time.sleep(1)
28                     IP = str(random.choice(self.iplist))
29                     proxy = {‘http‘,IP}
30                     return self.get(url, timeout, True,5)
31                 
32         else:#使用代理
33             
34             try:
35                 print ‘开始使用代理‘
36                 IP = random.choice(self.iplist)
37                 proxy = {‘http‘:IP}
38                 print proxy[‘http‘]
39                 return requests.get(url,headers=headers, timeout=timeout, proxies=proxy)
40             except:
41                 if num_retries>0:
42                     print u‘代理爬取网页错误,10s后继续尝试.....‘
43                     time.sleep(1)
44                     return self.get(url, timeout,True, num_retries-1)
45                 else:#代理也不行
46                     time.sleep(30)
47                     print u‘代理也没用...‘
48                     return None
49