How to downgrade python version from 3.8 to 3.7 (mac)

Consider installing pyenv with Homebrew on macOS

brew update
brew install pyenv

OR Clone the repository to get the latest version of pyenv

 git clone https://github.com/pyenv/pyenv.git ~/.pyenv

Define your environment variables (For a recent MacOS you may want to replace ~/.bash_profile with ~/.zshrc as that is the default shell)

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
source ~/.bash_profile

Restart your shell so the path changes take effect

exec "$SHELL"

Verify the installation and check the available python versions

pyenv install --list

Install the required python version

pyenv install 3.7

Set it as your global version after installation

pyenv global 3.7

Verify your current python version the system is using

python3 --version

brew only approach.

rm -rf $(brew --repository)/Library/Taps/company
brew tap-new company/team
brew extract [email protected] company/team  --version=3.7.9 
HOMEBREW_NO_AUTO_UPDATE=1  brew install company/team/[email protected]
brew link --force company/team/[email protected]

This creates a local tap, extracts python 3.7.X to a formula in that local tap and then installs and links that formula

The created local tap and the new formula file can be found in $(brew --repository)/Library/Taps/company/homebrew-team

I recommend you to install and use pyenv, a Python Version Management. Once intalled pyenv, install python 3.7:

pyenv install 3.7

And then set the environment PYENV_VERSION to version of python you want to use, on this case will be 3.7:

pyenv shell 3.7