直接pip install mysqlclient会出错，系统缺少对应的操作库
ubuntu系
sudo apt install libmysqlclient-dev pip install mysqlclient
centos系
yum install mysql-devel pip install mysqlclient
windows
在https://www.lfd.uci.edu/~gohlke/pythonlibs/网站上直接找对应的离线包下载安装