how to change python version 3.8 to 3.7 code example

Example 1: upgrade python to 3.8

$ sudo apt update -y
$ sudo apt install python3.8

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