replace /usr/bin/python3 homebrew 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: which python mac
$ brew update && brew upgrade python
ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python
$ brew update && brew upgrade python