4.xpath和BeautifulSoup4介绍

xpath语法：http://www.runoob.com/xpath/xpath-syntax.html

xpath开发工具：
1.Chrome插件：xpath helper
2.Firefox插件：xpath checker

XPath在python中的高级应用：https://blog.csdn.net/winterto1990/article/details/47903653

BeautifulSoup用法：https://cuiqingcai.com/1319.html

待更新...