Day2: Notes

.Request request a library crawling IMDb message
    - url request 
   https://movie.douban.com/top250
    - request method 
   GET 
   - request header 
   the User-Agent 
   Cookies 

two .selenium request library 
   1. What is selenium? 
      Opening is an automated testing tool 
      principle is to drive a certain good browser to perform some operation 
      on the reptile is essentially analog browser, so you can use it for reptiles 

    2. Why should I use selenium? 
      Advantages: 
          - js code execution 
          - no need to analyze complex communication process 
          - can do pop, pull down other operations on the browser 
          - ***** obtain dynamic data 
          - *** crack the login authentication 
      Disadvantages: 
          - low efficiency 
    3. installation and use
          ① install selenium request library: 
           PIP3 install selenium 

         ② must install the Google browser: 
           "Google" or Firefox 

         ③ drive installed browser:
         http://npm.taobao.org/mirrors/chromedriver/2.38/
           Windows: 
               Download win32 drive