Install Homebrew on Mac

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install pyenv to Manage Your Python Versions

brew install pyenv

Use pyenv to Install Python or Update Your Python Version

pyenv install 3.9.2

Set Up Your MacOS PATH for pyenv (Bash or ZSH)

For Bash

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n  eval "$(pyenv init --path)"\nfi' >> ~/.bash_profile
source  ~/.bash_profile

OR add the Open your ~/.bash_profile then add the commands below at the bottom

export PYENV_ROOT="$HOME/.pyenv"
export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init --path)"
eval "$(pyenv init -)"

For ZSH

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc
echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n  eval "$(pyenv init --path)"\nfi' >> ~/.zshrc
source ~/.zshrc

Troubleshooting:

Some guides will use eval "$(pyenv init -)" instead of eval "$(pyenv init --path)"

In my case eval "$(pyenv init --path)" worked

System:

• MacOS Majove v10.14.6
• Homebrew 3.2.5
• pyenv 2.0.4

How to remove Pyenv from mac

https://github.com/pyenv/pyenv#uninstalling-pyenv

The simplicity of pyenv makes it easy to temporarily disable it, or uninstall from the system.

1. To disable Pyenv managing your Python versions, simply remove the pyenv init invocations from your shell startup configuration. This will remove Pyenv shims directory from PATH, and future invocations like python will execute the system Python version, as it was before Pyenv.

   pyenv will still be accessible on the command line, but your Python apps won't be affected by version switching.

2. To completely uninstall Pyenv, remove all Pyenv configuration lines from your shell startup configuration, and then remove its root directory. This will delete all Python versions that were installed under the $(pyenv root)/versions/ directory:

   rm -rf $(pyenv root)

   If you've installed Pyenv using a package manager, as a final step, perform the Pyenv package removal. For instance, for Homebrew:

   brew uninstall pyenv
   

Sources:

https://www.freecodecamp.org/news/python-version-on-mac-update/

pyenv/pyenv#849