伪造随机的User-Agent

写好爬虫的原则只有一条:

就是让你的抓取行为和用户访问网站的真实行为尽量一致

1、伪造UA字符串，每次请求都使用随机生成的UA

为了减少复杂度，随机生成UA的功能通过第三方模块库fake-useragent实现，使用pip进行安装

1	pip install fake-useragent

2、生成一个UA字符串只需要如下代码

1 2	from fake_useragent import UserAgent  ua = UserAgent()

各浏览器的User-Agent

这个库还有一个其他的功能，就是可以随机各浏览器的UA

IE浏览器的UA：

1	print(ua.ie)

Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)

Opera浏览器的UA：

1	print(ua.opera)

Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.6.37 Version/11.00

Chrome浏览器的UA：

1	print(ua.chrome)

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.2 (KHTML, like Gecko) Chrome/22.0.1216.0 Safari/537.2

Firefox浏览器的UA：

1	print(ua.firefox)

Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:16.0.1) Gecko/20121011 Firefox/16.0.1

Safari浏览器的UA：

1	print(ua.safari)

Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5355d Safari/8536.25

随机User-Agent

写爬虫最实用的就是可以随意变换headers，一定要有随机性

在这里我写了三个随机生成UA，三次打印都不一样，随机性很强，十分方便

1 2 3

print(ua.random) print(ua.random) print(ua.random)

Mozilla/5.0 (X11; CrOS i686 3912.101.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, likeGecko) Chrome/37.0.2062.124 Safari/537.36

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1664.3 Safari/537.36

当然，你如果不想这么用的话，你也可以自己搜集一些UA，存为文本文件，然后打开读取来用

附：常用的User-Agent列表

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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", ]