linux 安装python3.8.3

参见：https://blog.csdn.net/caimouse/article/details/106447071

依赖库：zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel libffi-devel

要先安装 libffi-devel，否则之后c++中 import 库会报错：ModuleNotFoundError: No module named '_ctypes'

安装之后：修改了/usr/bin/python的指向，会导致yum安装报错

 

 解决方法：

　　打开报错的文件，将第一行#!/usr/bin/python 改为：#!/usr/bin/python2

参见：https://blog.csdn.net/eaxy_z/article/details/80798061