pyenv

pyenv is a Python version management tool that allows you to install and manage multiple Python versions in parallel. It is particularly useful for developers who need to work with different Python versions.

Installation and Setup

Dependencies and Installation

Before you can install pyenv, you need to install some dependencies. The required packages differ depending on your Linux distribution:

Ubuntu/Debian

sudo apt-get update
sudo apt-get install -y make build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm \
libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev

Fedora

sudo dnf install -y make gcc zlib-devel bzip2 bzip2-devel readline-devel \
sqlite sqlite-devel openssl-devel xz xz-devel libffi-devel findutils

Arch Linux

sudo pacman -S --needed base-devel openssl zlib xz tk

The installation of pyenv consists of three steps:

Clone the pyenv repository:

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

Add pyenv to your shell configuration. Choose the configuration for your shell:

For bash

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bashrc
echo 'command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc

For zsh

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc
echo 'command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc
echo 'eval "$(pyenv init -)"' >> ~/.zshrc

Reload your shell configuration:

For bash
```
source ~/.bashrc
```
For zsh
```
source ~/.zshrc
```

Basic Usage and Python Versions

Managing Python Versions

To install a new Python version, use the following command:

pyenv install 3.12.3

To use a Python version globally, execute this command:

pyenv global 3.12.3

To use a Python version for a specific directory, execute this command in the desired directory:

pyenv local 3.12.3

To show all installed Python versions, use:

pyenv versions

Advanced Features and Plugins

Virtual Environments and Plugin System

pyenv supports virtual environments through the pyenv-virtualenv plugin. The setup consists of three steps:

Install the plugin:

git clone https://github.com/pyenv/pyenv-virtualenv.git $(pyenv root)/plugins/pyenv-virtualenv

Create a virtual environment:
```
pyenv virtualenv 3.12.3 myenv
```
Activate the virtual environment:
```
pyenv activate myenv
```

pyenv can automatically select the right Python version based on a .python-version file. Create the file with:

echo "3.12.3" > .python-version

pyenv supports various plugins for additional functionality:

pyenv-virtualenv: Virtual environments
pyenv-which-ext: Extended path resolution
pyenv-update: Automatic updates

System Management and Troubleshooting

System Status and Maintenance

To check the currently used Python version:

pyenv version

When you've installed new Python binaries, execute this command:

pyenv rehash

For seamless integration with your shell, add these lines to your shell configuration:

# For zsh
eval "$(pyenv init --path)"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"

Troubleshooting

If you encounter issues, proceed as follows:

Check your shell configuration
Ensure all dependencies are installed
Verify the permissions of pyenv directories
Consult the official pyenv documentation