pyenv / pyenv

# Simple Python Version Management: pyenv
pyenv lets you easily switch between multiple versions of Python. It's
simple, unobtrusive, and follows the UNIX tradition of single-purpose
tools that do one thing well.
This project was forked from rbenv and
ruby-build, and modified for Python.
### What pyenv _does..._
* Lets you **change the global Python version** on a per-user basis.
* Provides support for **per-project Python versions**.
* Supports **multiple Python distributions**: CPython, PyPy, Stackless Python, Jython, and more.
 See the full list of available versions.
* Allows you to **override the Python version** with an environment
 variable.
* Searches for commands from **multiple versions of Python at a time**.
 This may be helpful to test across Python versions with tox.
### In contrast with pythonbrew and pythonz, pyenv _does not..._
* **Depend on Python itself.** pyenv was made from pure shell scripts.
 There is no bootstrap problem of Python.
* **Need to be loaded into your shell.** Instead, pyenv's shim
 approach works by adding a directory to your `PATH`.
* **Manage virtualenv.** Of course, you can create virtualenv
 yourself, or pyenv-virtualenv
 to automate the process.
----
## Table of Contents
* **Installation**
 * Getting Pyenv
 * Linux/UNIX
 * Automatic Installer
 * Basic GitHub Checkout
 * MacOS
 * Homebrew in macOS
 * Windows
 * Set up your shell environment for Pyenv
 * Restart your shell
 * Install Python build dependencies
 * Upgrade Notes
* **Usage**
 * Install additional Python versions
 * Prefix auto-resolution to the latest version
 * Python versions with extended support
 * Switch between Python versions
 * Making multiple versions available
 * Uninstall Python versions
 * Other operations
* Upgrading
 * Upgrading with Homebrew
 * Upgrading with Installer or Git checkout
* Uninstalling pyenv
* Pyenv plugins
* **How It Works**
 * Understanding PATH
 * Understanding Shims
 * Understanding Python version selection
 * Locating Pyenv-provided Python Installations
* Advanced Configuration
 * Using Pyenv without shims
 * Running nested shells from Python-based programs
 * Environment variables
 * Manual shell setup
* **Development**
 * Contributing
 * Version History
 * License
----
## Installation
### A. Getting Pyenv
----
#### Linux/Unix
The Homebrew option from the MacOS section below would also work if you have Homebrew installed.
##### 1. Automatic installer (Recommended)
 [code] 
For more details visit our other project:
https://github.com/pyenv/pyenv-installer
##### 2. Basic GitHub Checkout
This will get you going with the latest version of Pyenv and make it
easy to fork and contribute any changes back upstream.
* **Check out Pyenv where you want it installed.**
 A good place to choose is `$HOME/.pyenv` (but you can install it somewhere else):
 [code] 
* Optionally, try to compile a dynamic Bash extension to speed up Pyenv. Don't
 worry if it fails; Pyenv will still work normally:
 [code] 
#### MacOS
The options from