pandas csv reference

https://blog.csdn.net/asdfgh0077/article/details/106947477/

https://blog.csdn.net/u010665216/article/details/78559091

https://www.csdn.net/tags/MtTaMg1sMTc1ODI3LWJsb2cO0O0O.html

https://www.pythonheidong.com/blog/article/472551/34bd354bebf3d91551da/

https://blog.csdn.net/qq_39332551/article/details/117664369

https://wenku.baidu.com/view/3224525f1411cc7931b765ce0508763231127409.html