macbook upgrade from python3,7 to 3,8 code example
Example 1: how to set default python version in macos
ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python
Example 2: mac catallina python3
$ brew install pyenv
ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python
$ brew install pyenv