https://www.cnblogs.com/Axi8/p/5757270.html
https://www.cnblogs.com/Axi8/p/5773269.html
https://www.runoob.com/w3cnote/python-spider-intro.html
http://c.biancheng.net/view/2011.html
http://www.imooc.com/learn/563
https://www.cnblogs.com/Axi8/p/5757270.html
https://www.cnblogs.com/Axi8/p/5773269.html
https://www.runoob.com/w3cnote/python-spider-intro.html
http://c.biancheng.net/view/2011.html
http://www.imooc.com/learn/563