Python-100-Days/Day66-75/常见反爬策略及应对方案.md

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常见反爬策略及应对方案

  1. 构造合理的HTTP请求头。

    • Accept

    • User-Agent - 三方库fake-useragent

      from fake_useragent import UserAgent
      ua = UserAgent()
      
      ua.ie
      # Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US);
      ua.msie
      # Mozilla/5.0 (compatible; MSIE 10.0; Macintosh; Intel Mac OS X 10_7_3; Trident/6.0)'
      ua['Internet Explorer']
      # Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.4; InfoPath.2; SV1; .NET CLR 3.3.69573; WOW64; en-US)
      ua.opera
      # Opera/9.80 (X11; Linux i686; U; ru) Presto/2.8.131 Version/11.11
      ua.chrome
      # Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.2 (KHTML, like Gecko) Chrome/22.0.1216.0 Safari/537.2'
      ua.google
      # Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4) AppleWebKit/537.13 (KHTML, like Gecko) Chrome/24.0.1290.1 Safari/537.13
      ua['google chrome']
      # Mozilla/5.0 (X11; CrOS i686 2268.111.0) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 Safari/536.11
      ua.firefox
      # Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:16.0.1) Gecko/20121011 Firefox/16.0.1
      ua.ff
      # Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:15.0) Gecko/20100101 Firefox/15.0.1
      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
      
      # and the best one, random via real world browser usage statistic
      ua.random
      
    • Referer

    • Accept-Encoding

    • Accept-Language

  2. 检查网站生成的Cookie。

    • 有用的插件:EditThisCookie
    • 如何处理脚本动态生成的Cookie
  3. 抓取动态内容。

    • Selenium + WebDriver
    • Chrome / Firefox - Driver
  4. 限制爬取的速度。

  5. 处理表单中的隐藏域。

    • 在读取到隐藏域之前不要提交表单
    • 用RoboBrowser这样的工具辅助提交表单
  6. 处理表单中的验证码。

    • OCRTesseract - 商业项目一般不考虑

    • 专业识别平台 - 超级鹰 / 云打码

      from hashlib import md5
      
      class ChaoClient(object):
      
          def __init__(self, username, password, soft_id):
              self.username = username
              password =  password.encode('utf-8')
              self.password = md5(password).hexdigest()
              self.soft_id = soft_id
              self.base_params = {
                  'user': self.username,
                  'pass2': self.password,
                  'softid': self.soft_id,
              }
              self.headers = {
                  'Connection': 'Keep-Alive',
                  'User-Agent': 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)',
              }
      
          def post_pic(self, im, codetype):
              params = {
                  'codetype': codetype,
              }
              params.update(self.base_params)
              files = {'userfile': ('captcha.jpg', im)}
              r = requests.post('http://upload.chaojiying.net/Upload/Processing.php', data=params, files=files, headers=self.headers)
              return r.json()
      
      
      if __name__ == '__main__':
          client = ChaoClient('用户名', '密码', '软件ID')
          with open('captcha.jpg', 'rb') as file:                                                
              print(client.post_pic(file, 1902))                                          
      
  7. 绕开“陷阱”。

    • 网页上有诱使爬虫爬取的爬取的隐藏链接(陷阱或蜜罐)
    • 通过Selenium+WebDriver+Chrome判断链接是否可见或在可视区域
  8. 隐藏身份。