AI&BigData训练营笔记三：Python爬虫攻破反爬虫防御策略
系统环境：
操作系统：Windows8.1专业版 64bit
Python：anaconda、Python2.7
Python modules:requests、json、random、timeBackground：
在使用Python爬虫爬取网页数据时，我们会遭到网站自身的反爬虫防御，这时候我们需要采取一些方法来攻破网站的反爬虫防御策略。
解决方法：
接下来，将使用伪装浏览器UA、IP代理、爬虫频率控制这三种方法来攻破网站的反爬虫防御策略。在编程实现之前，需要按照以上的系统环境，配置好自己的Python环境。
# -*- coding: utf-8 -*-
"""
Created on Sun Apr 22 17:08:29 2018
@author: gmn
"""
#导入requests module
import requests
#导入json module
import json
#导入random module
import random
#导入time module
import time
#User-Agent列表，这个可以自己在网上搜到
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",
]
#设置IP代理
proxies={"http":"http://41.118.132.69:4433"}
#爬取100次
for index in range(100):
print '第%d次爬取：' % (index+1)
#设置要爬取的url
url='http://money.finance.sina.com.cn/d/api/openapi_proxy.php/?__s=[[%22bkshy%22,%22%22,0]]'
#设置get请求的User-Agent，用于伪装浏览器UA
headers={'User-Agent':random.choice(USER_AGENTS)}
#requests get请求
req=requests.get(url,headers=headers,proxies=proxies)
#加载json数据
jsinfo=json.loads(req.content)
#测试：打印爬取到的json数据
print jsinfo[0]['count']
#设置爬取频率
time.sleep(5) #延时5秒