How to install python3.7 on a mac (mojave using homebrew
The following procedure worked for me (in addition to the commands in the original question):
brew uninstall --ignore-dependencies python3
brew uninstall --force python#3.8
brew install python3

and adding the following line to .bash_profile:
alias python=&quot;python3&quot;

For a Mac this was really easy! Only about 10 commands.