Mac 修改默认python的版本

1.安装Python 3
从官网下载：https://www.python.org/getit/

2.查看Python3 安装路径
打开终端，输入which python3，查看路径 /Library/Frameworks/Python.framework/Versions/3.7/bin/python3

3.打开配置文件
vim ~/.bash_profile

4.写入外部环境变量
export PATH=${PATH}:/Library/Frameworks/Python.framework/Versions/3.7/bin/python3

5.重命名Python
alias python="/Library/Frameworks/Python.framework/Versions/3.7/bin/python3"

6.关闭文件

7.终端执行命令：

source ~/.bash_profile

8.终端执行命令： python检查Python版本

python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>