How to Install and Use Pyenv for Python Version Management

Managing multiple Python versions can be challenging, especially when different projects require different Python environments. Pyenv is a lightweight, easy-to-use tool that allows developers to install, switch, and manage multiple Python versions seamlessly. This guide covers the most commonly used Pyenv commands and provides step-by-step instructions to configure it on both Windows and macOS.

What is Pyenv?

Pyenv is a Python version management tool that allows you to:

Install multiple versions of Python.
Easily switch between different Python versions.
Set a global or local Python version for specific projects.
Work with virtual environments efficiently.

Unlike system-installed Python, Pyenv lets you work with isolated Python versions without interfering with system dependencies.

Installing Pyenv on macOS

Step 1: Install Homebrew (if not installed)

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

Step 2: Install Pyenv

brew update
brew install pyenv

Step 3: Configure Shell for Pyenv

Add the following to your shell configuration file (~/.zshrc or ~/.bashrc):

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

Step 4: Verify Installation

pyenv --version

Installing Pyenv on Windows

On Windows, you should use Pyenv for Windows, which is a separate fork.

Step 1: Install Pyenv for Windows

Download and install pyenv-win using PowerShell:

winget install pyenv-win

Step 2: Configure Environment Variables

Manually add the following paths to your system Environment Variables:

C:\Users\YourUser\.pyenv\pyenv-win\bin
C:\Users\YourUser\.pyenv\pyenv-win\shims

Step 3: Verify Installation

pyenv --version

Commonly Used Pyenv Commands

1. List all available versions

pyenv install --list

2. Install a Specific Python Version

pyenv install 3.10.4

3. List All Available Python Versions

pyenv install --list

4. Set a Global Python Version (Used across all projects)

pyenv global 3.10.4

5. Set a Local Python Version (For a specific project)

cd my_project
pyenv local 3.9.7

6. Show the Current Python Version

pyenv version

7. Uninstall a Python Version

pyenv uninstall 3.9.7

8. Update Pyenv

pyenv update

9. List All Installed Python Versions

pyenv versions

10. List all available virtual envs

pyenv virtualenvs

11. Create a virtualenv using pyenv

pyenv virtualenv 3.10.0 myenv

12. Activate a virtualenv

pyenv activate myenv

13. Rehash Pyenv (Necessary After Installing New Versions)

pyenv rehash

14. Uninstall Pyenv (If Needed)

For macOS:

brew uninstall pyenv
rm -rf ~/.pyenv

For Windows:

winget uninstall pyenv-win

Conclusion

Pyenv is an essential tool for developers working with multiple Python versions. By following the steps in this guide, you can easily configure and use Pyenv on both Windows and macOS. Whether you are switching Python versions, setting up project-specific environments, or ensuring compatibility, Pyenv simplifies Python version management. Start using Pyenv today and take full control of your Python development workflow! 🚀