电脑系统升级后，python报错，解决方案：
使用repo命令，提示需要安装python；安装后还是一直提示安装；
sudo ln -s /Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/bin/python3.8 /usr/local/bin/python3
sudo ln -s -f /usr/local/bin/python3 /usr/local/bin/python
执行以上两行命令，会在/usr/local/bin/目录下生成，python3与python的快捷引用方式；
注意此目录为你的python目录（版本需要对应自己的版本号）：/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/bin/python3.8
which python3查找python路径
参考链接：
Python3
https://www.zhihu.com/question/420273182
http://events.jianshu.io/p/046da62bd527
https://cloud.tencent.com/developer/article/1967674
/usr/local/bin/python3
/usr/bin/python3
