how to set python on mac code example

Example 1: which python mac

$ brew update && brew upgrade python

Example 2: set python3 as default mac

# it is said not to do but I used it anyway, because of the conveniency
$ echo "alias python=/usr/local/bin/python3.7" >> ~/.zshrc

Example 3: install python in mac

brew install python3
brew install python2

Example 4: set python 3 as default mac

[ -e ~/.profile ] && . ~/.profile