change python version mac to 3.8 code example

Example 1: mac upgrade python to 3.8

brew install python3
brew update && brew upgrade python
alias python=/usr/local/bin/python3

Example 2: how to set default python version in macos

ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python

Example 3: 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