Managing Python Versions with pyenv

In earlier years, Conda was predominantly used for managing Python environments. Nowadays, pyenv is commonly employed.

This article aims to document the installation and usage of pyenv.

Prerequisites​

Before installing pyenv, ensure that Git is installed on your system.

Installing pyenv​

1. Execute Installation Command:

   You can quickly install pyenv by running the following command:

   curl https://pyenv.run | bash
   

   This command fetches and executes the installation script from the pyenv-installer repository on GitHub.

2. Configure Your Shell Environment:

   After installation, follow the setup guide to configure your shell environment to ensure that pyenv works correctly.

   If you are using bash, add the following code to your .bashrc file:

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

   For zsh users, add the above code to your .zshrc file.

3. Restart Your Shell:

   After completing the above steps, reload the new configuration.

   exec $SHELL
   

Using pyenv​

Once installed and configured, you can start using pyenv to manage multiple Python versions:

• Install a New Python Version:

  pyenv install 3.10.14
  

• Switch the Global Python Version:

  pyenv global 3.10.14
  

• Use a Specific Version in a Directory:

  pyenv local 3.8.5
  

Virtual Environments​

Virtual environments are crucial in Python development.

They allow us to use different Python versions and dependencies in different projects.

At the very least, when you accidentally mess up your Python environment, you can simply delete the virtual environment and start over.

Installation​

pyenv also provides a pyenv-virtualenv plugin, making it easier to manage Python virtual environments.

Previously, this feature required separate installation, but it's now integrated into pyenv, and we can directly use:

pyenv virtualenv 3.10.14 your-env-name

Here, 3.10.14 is the Python version you want to use, which you've already installed in the previous step, and your-env-name is the name of the virtual environment.

Usage​

To activate the virtual environment, run:

pyenv activate your-env-name

Removal​

Finally, when you no longer need the virtual environment, you can run the following command to delete it:

pyenv virtualenv-delete your-env-name

Updating pyenv​

To update pyenv to the latest version, simply run:

pyenv update

Uninstalling pyenv​

If you decide to no longer use pyenv, follow these steps to uninstall:

1. Remove the pyenv Installation Directory:

   rm -fr ~/.pyenv
   

2. Clean Your .bashrc:

   Remove or comment out the relevant pyenv configuration lines, then restart your shell:

   exec $SHELL