Setting up Pyenv and Pyenv-virtualenv

I want to start using python 3 but can't give up python 2.7 because of other project that rely on it. I've had a few people mention that I should use pyenv for virtual environments in the past but I didn't feel like learning another tool. Now that I want to give python 3 a try I searched around on different ways to have more than one python version on a system and Pyenv was mentioned a lot. Since I've been in the mood to try to document how I install tools, utilize tools, pickup new techniques, etc.. I felt this is a great opportunity to both document and write a quick article about it.

Enter: pyenv and pyenv-virtualenv

Installation and setup on mac with homebrew

brew update
brew install pyenv
brew install pyenv-virtualenv

Add these lines to the end of your .zshrc/.bashrc

# set paths
export PATH=/usr/local/bin:$PATH
export PYENV_ROOT="$HOME/.pyenv"
export PATH="$PYENV_ROOT/bin:$PATH"
# initialize pyenv on terminal load
eval "$(pyenv init -)"
# auto ativate virtualenv for pyenv
if which pyenv-virtualenv-init > /dev/null; then eval "$(pyenv virtualenv-init -)"; fi

# python virtual env
if [ -z ${VIRTUAL_ENV+x} ]
then
VENV_NOTICE=""
else
VENV_NOTICE=" (py: $(basename "$VIRTUAL_ENV"))"
fi

Pyenv Commands

List all python versions downloaded

pyenv versions

View what python version is currently activated

pyenv version

View what python version is set to global

pyenv global

Install python version 2.7.8 or any python version

pyenv install 2.7.8

Rehash after instaling any python version

pyenv rehash

Set global python version

pyenv global 2.7.8

Set python version for current directory This also creates a .python-version in current directory

pyenv local 3.5.0

Pyenv-virtualenv Commands

Create virtualenv with python version 2.7.8 and name the env project_name

pyenv virtualenv 2.7.8 project_name pyenv virtualenv [pyenv-version] [virtualenv-name]

List virtualenvs already created, also shows py version for each env

pyenv virtualenvs

Activate a virtualenv from one thats already made

pyenv local venv_name

Deactivate a virtualenv

pyenv deactivate

Pyenv and Pyenv-virtualenv Commands

Remove a Python version or virtualenv

pyenv uninstall <virtualenv or python-version>