How to Get Pyenv Up and Running

A Comprehensive Guide for Managing Python Versions on MacOS and Windows

Managing multiple Python versions can be a hassle, but with pyenv, it becomes a seamless process. Whether you're working on a Windows or MacOS system, pyenv helps you easily switch between different Python versions for different projects. This guide will walk you through the steps to install and set up pyenv on both Windows and MacOS.

Introduction

pyenv is a powerful tool that allows you to easily install and switch between multiple versions of Python. This is especially useful when working on projects that require different Python versions. With `pyenv`, you can manage your Python versions independently from the system Python, ensuring compatibility and avoiding conflicts.

Prerequisites

Before you begin, ensure you have the following:

• Basic knowledge of using the command line.

• Administrator access to your system.

Installing pyenv on MacOS

Step 1: Install Homebrew

Homebrew is a popular package manager for MacOS. If you don't have Homebrew installed, you can install it by running the following command in your terminal:

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

Step 2: Install pyenv

With Homebrew installed, you can now install `pyenv` by running:

brew update

brew install pyenv

See here if you need to install homebrew

Step 3: Configure your shell

To ensure pyenv works correctly, you need to add it to your shell configuration. Add the following lines to your `.bash_profile`, `.zshrc`, or other relevant shell configuration file:

if command -v pyenv &> /dev/null; then 
    eval "$(pyenv init --path)"
    eval "$(pyenv init -)"
fi

After adding the lines, reload your shell configuration:

source ~/.bash_profile

Step 4: Verify installation

To verify that `pyenv` is installed correctly, run:

pyenv --version

You should see the version of `pyenv` installed.

Installing pyenv on Windows

Step 1: Install prerequisites

Before installing `pyenv` on Windows, you need to install some prerequisites:

• Git for Windows

• Python (ensure you add Python to PATH during installation)

• Visual Studio Code https://code.visualstudio.com/ (optional, but recommended)

Step 2: Install pyenv-win

Clone the `pyenv-win` repository to your local machine:

git clone https://github.com/pyenv-win/pyenv-win.git %USERPROFILE%\.pyenv

Step 3: Add pyenv to system PATH

Add the following paths to your system PATH environment variable:

%USERPROFILE%\.pyenv\pyenv-win\bin
%USERPROFILE%\.pyenv\pyenv-win\shims

To do this, follow these steps:

1. Open the Start Menu and search for "Environment Variables".

2. Click on "Edit the system environment variables".

3. In the System Properties window, click on "Environment Variables".

4. Under "System variables", find and select the `Path` variable, then click "Edit".

5. Add the paths mentioned above to the list.

Step 4: Verify installation

To verify that `pyenv` is installed correctly, open a new Command Prompt or PowerShell window and run:

pyenv --version

You should see the version of `pyenv` installed.

Using pyenv

Installing Python versions

With `pyenv` installed, you can now install different versions of Python. For example, to install Python 3.9.5, run:

pyenv install 3.9.5

Setting global and local Python versions

You can set the global Python version (the default version) with:

pyenv global 3.9.5

To set a local Python version for a specific project, navigate to the project directory and run:

pyenv local 3.8.10

This will create a `.python-version` file in the project directory specifying the Python version.

Listing installed versions

To list all Python versions installed via `pyenv`, run:

pyenv versions

Conclusion

Managing multiple Python versions is made simple and efficient with pyenv. Whether you're using MacOS or Windows, following the steps in this guide will help you set up pyenv and streamline your development workflow. With pyenv, you can ensure compatibility across different projects and avoid conflicts with system Python versions, making your development process smoother and more productive.

Happy coding!