Pyenv

What is it

pyenv is a command-line program that helps you control which flavor and version of Python you wish to use. This makes it really easy to switch from stock Python to conda to minipython to jython to pypy. It also provides fine-grained control over version numbers for each flavor.

$ pyenv install -l Available versions: 2.1.3 2.2.3 2.3.7 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.4.5 2.4.6 2.5 2.5.1 2.5.2 2.5.3 2.5.4 2.5.5 2.5.6 2.6.6 2.6.7 2.6.8 2.6.9 2.7-dev 2.7 2.7.1 2.7.2 2.7.3 2.7.4 2.7.5 2.7.6 2.7.7 2.7.8 2.7.9 2.7.10 2.7.11 2.7.12 2.7.13 2.7.14 3.0.1 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.3.0 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 3.4.0 3.4-dev 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.4.7 3.5.0 3.5-dev 3.5.1 3.5.2 3.5.3 3.5.4 3.6.0 3.6-dev 3.6.1 3.6.2 3.6.3 3.6.4 3.7.0a3 3.7-dev anaconda-1.4.0 anaconda-1.5.0 anaconda-1.5.1 anaconda-1.6.0 anaconda-1.6.1 anaconda-1.7.0 anaconda-1.8.0 anaconda-1.9.0 anaconda-1.9.1 anaconda-1.9.2 anaconda-2.0.0 anaconda-2.0.1 anaconda-2.1.0 anaconda-2.2.0 anaconda-2.3.0 anaconda-2.4.0 anaconda-4.0.0 anaconda2-2.4.0 anaconda2-2.4.1 anaconda2-2.5.0 anaconda2-4.0.0 anaconda2-4.1.0 anaconda2-4.1.1 anaconda2-4.2.0 anaconda2-4.3.0 anaconda2-4.3.1 anaconda2-4.4.0 anaconda2-5.0.0 anaconda2-5.0.1 anaconda3-2.0.0 anaconda3-2.0.1 anaconda3-2.1.0 anaconda3-2.2.0 anaconda3-2.3.0 anaconda3-2.4.0 anaconda3-2.4.1 anaconda3-2.5.0 anaconda3-4.0.0 anaconda3-4.1.0 anaconda3-4.1.1 anaconda3-4.2.0 anaconda3-4.3.0 anaconda3-4.3.1 anaconda3-4.4.0 anaconda3-5.0.0 anaconda3-5.0.1 ironpython-dev ironpython-2.7.4 ironpython-2.7.5 ironpython-2.7.6.3 ironpython-2.7.7 jython-dev jython-2.5.0 jython-2.5-dev jython-2.5.1 jython-2.5.2 jython-2.5.3 jython-2.5.4-rc1 jython-2.7.0 jython-2.7.1 micropython-dev micropython-1.9.3 miniconda-latest miniconda-2.2.2 miniconda-3.0.0 miniconda-3.0.4 miniconda-3.0.5 miniconda-3.3.0 miniconda-3.4.2 miniconda-3.7.0 miniconda-3.8.3 miniconda-3.9.1 miniconda-3.10.1 miniconda-3.16.0 miniconda-3.18.3 miniconda2-latest miniconda2-3.18.3 miniconda2-3.19.0 miniconda2-4.0.5 miniconda2-4.1.11 miniconda2-4.3.14 miniconda2-4.3.21 miniconda2-4.3.27 miniconda2-4.3.30 miniconda3-latest miniconda3-2.2.2 miniconda3-3.0.0 miniconda3-3.0.4 miniconda3-3.0.5 miniconda3-3.3.0 miniconda3-3.4.2 miniconda3-3.7.0 miniconda3-3.8.3 miniconda3-3.9.1 miniconda3-3.10.1 miniconda3-3.16.0 miniconda3-3.18.3 miniconda3-3.19.0 miniconda3-4.0.5 miniconda3-4.1.11 miniconda3-4.2.12 miniconda3-4.3.11 miniconda3-4.3.14 miniconda3-4.3.21 miniconda3-4.3.27 miniconda3-4.3.30 pypy-c-jit-latest pypy-c-nojit-latest pypy-dev pypy-stm-2.3 pypy-stm-2.5.1 pypy-1.5-src pypy-1.5 pypy-1.6 pypy-1.7 pypy-1.8 pypy-1.9 pypy-2.0-src pypy-2.0 pypy-2.0.1-src pypy-2.0.1 pypy-2.0.2-src pypy-2.0.2 pypy-2.1-src pypy-2.1 pypy-2.2-src pypy-2.2 pypy-2.2.1-src pypy-2.2.1 pypy-2.3-src pypy-2.3 pypy-2.3.1-src pypy-2.3.1 pypy-2.4.0-src pypy-2.4.0 pypy-2.5.0-src pypy-2.5.0 pypy-2.5.1-src pypy-2.5.1 pypy-2.6.0-src pypy-2.6.0 pypy-2.6.1-src pypy-2.6.1 pypy-4.0.0-src pypy-4.0.0 pypy-4.0.1-src pypy-4.0.1 pypy-5.0.0-src pypy-5.0.0 pypy-5.0.1-src pypy-5.0.1 pypy-5.1-src pypy-5.1 pypy-5.1.1-src pypy-5.1.1 pypy-5.3-src pypy-5.3 pypy-5.3.1-src pypy-5.3.1 pypy-5.4-src pypy-5.4 pypy-5.4.1-src pypy-5.4.1 pypy-5.6.0-src pypy-5.6.0 pypy-5.7.0-src pypy-5.7.0 pypy-5.7.1-src pypy-5.7.1 pypy2-5.3-src pypy2-5.3 pypy2-5.3.1-src pypy2-5.3.1 pypy2-5.4-src pypy2-5.4 pypy2-5.4.1-src pypy2-5.4.1 pypy2-5.6.0-src pypy2-5.6.0 pypy2-5.7.0-src pypy2-5.7.0 pypy2-5.7.1-src pypy2-5.7.1 pypy2.7-5.8.0-src pypy2.7-5.8.0 pypy2.7-5.9.0-src pypy2.7-5.9.0 pypy2.7-5.10.0-src pypy2.7-5.10.0 pypy3-dev pypy3-2.3.1-src pypy3-2.3.1 pypy3-2.4.0-src pypy3-2.4.0 pypy3.3-5.2-alpha1-src pypy3.3-5.2-alpha1 pypy3.3-5.5-alpha-src pypy3.3-5.5-alpha pypy3.5-c-jit-latest pypy3.5-5.7-beta-src pypy3.5-5.7-beta pypy3.5-5.7.1-beta-src pypy3.5-5.7.1-beta pypy3.5-5.8.0-src pypy3.5-5.8.0 pypy3.5-5.9.0-src pypy3.5-5.9.0 pypy3.5-5.10.0-src pypy3.5-5.10.0 pyston-0.5.1 pyston-0.6.0 pyston-0.6.1 stackless-dev stackless-2.7-dev stackless-2.7.2 stackless-2.7.3 stackless-2.7.4 stackless-2.7.5 stackless-2.7.6 stackless-2.7.7 stackless-2.7.8 stackless-2.7.9 stackless-2.7.10 stackless-2.7.11 stackless-2.7.12 stackless-2.7.14 stackless-3.2.2 stackless-3.2.5 stackless-3.3.5 stackless-3.3.7 stackless-3.4-dev stackless-3.4.1 stackless-3.4.2 stackless-3.4.7 stackless-3.5.4

Installing

Mac OS X

Fortunately, pyenv is available through Homebrew on Mac OS X.

brew install pyenv

Debian

To install pyenv on Debian, use the pyenv-installer script provided by the author of pyenv.

Link: https://github.com/pyenv/pyenv-installer

curl -L https://raw.githubusercontent.com/pyenv/pyenv-installer/master/bin/pyenv-installer | bash

Add to Path

You should add ~/.pyenv/bin to your path if the script did not do that automatically for you..

Basic Usage

To set a python version from the list above, start by installing it.

Example: Anaconda

Let's look at anaconda as an example. Install via pyenv install command:

pyenv install anaconda3-5.0.1

To set that particular python distribution as the global python version, use the pyenv global command:

pyenv global anaconda3-5.0.1

To switch to that version of conda, you need to execute the commands spit out by the pyenv init - command:

$ pyenv init -
export PATH="/Users/charles/.pyenv/shims:${PATH}"
export PYENV_SHELL=bash
command pyenv rehash 2>/dev/null
pyenv() {
  local command
  command="$1"
  if [ "$#" -gt 0 ]; then
    shift
  fi

  case "$command" in
  rehash|shell)
    eval "$(pyenv "sh-$command" "$@")";;
  *)
    command pyenv "$command" "$@";;
  esac
}

To actually execute this code, wrap it in an eval command:

eval "$(pyenv init -)"

Now you should see conda on your path:

$ eval "$(pyenv init -)"

$ which conda
/Users/charles/.pyenv/shims/conda