pyenv cheat sheet

pyenv-cheat-sheet.md

Python environment cheatsheet

virtualenv

Tool for creating isolated Python environments

The common use-cases:

• Handling different versions of same libraries per each service
• Same plus no access to site-packages

In all these cases, virtualenv can help. It creates an environment that has its own installation directories, that doesn’t share libraries with other virtualenv environments (and optionally doesn’t access the globally installed libraries either).

virtualenvwrapper

Extension scripts for virtualenv

1. Organizes all of your virtual environments in one place
2. Wrappers for managing your virtual environments (create, delete, copy)
3. Use a single command to switch between environments
4. Tab completion for commands that take a virtual environment as argument

pyenv

Tool for switching between different versions of Python interpreter

Intercepts Python commands using shim executables injected into your PATH, determines which Python version has been specified by your application, and passes your commands along to the correct Python installation

command reference

pyenv-viertualenv

PyEnv plugin that provides features to manage virtualenvs and conda environments for Python on UNIX-like systems

Features:

• additional commands activate, deactivate, ...
• auto activation and deactivation on directory enter/leave events (using .python-version file)

pyenv-viertualenvwrapper

PyEnv plugin which provides a pyenv virtualenvwrapper command to manage virtualenvs with virtualenvwrapper

Install

virtualenv + virtualenvwrapper

sudo -H pip install virtualenv

~/.bashrc

export WORKON_HOME=$HOME/.virtualenvs
export PROJECT_HOME=$HOME/workspace
mkdir -p $PROJECT_HOME

pyenv + pyenv-virtualenv

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

~/.bashrc

export PATH="$HOME/.pyenv/bin:$PATH"
export PYENV_VIRTUALENVWRAPPER_PREFER_PYVENV=1
eval "$(pyenv init -)"

source ~/.bashrc

pyenv-virtualenvwrapper

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

Satisfy pyenv build requirements

sudo apt-get install -y \
    make \
    build-essential \
    libssl-dev \
    zlib1g-dev \
    libbz2-dev \
    libreadline-dev \
    libsqlite3-dev \
    wget \
    curl \
    llvm \
    libncurses5-dev \
    libncursesw5-dev \
    xz-utils \
    libffi-dev \
    libssl1.0-dev

Install some basic Python version for virtualenvwrapper and install it inside

pyenv install <basic_python_version>
pyenv global <basic_python_version>
pip install virtualenvwrapper

~/.bashrc

pyenv virtualenvwrapper_lazy

Update

pyenv update

Uninstall

rm -rf $(pyenv root)
sudo -H pip uninstall -y virtualenv virtualenvwrapper

Remove added ~/.bashrc records related to virtualenv/virtualenvwrapper/pyenv

Workflow: New project

1. Install latest CPython 2.7

   pyenv install 2.7-dev

2. Create new project and environment (both with the same name project_name)

   mkproject <project_name>

3. Set Python version

   pyenv shell 2.7-dev

4. Working on a project ...

5. Exit environment

   source deactivate

6. Enter environment workon <project_name>

   workon <project_name>

7. Working on a project ...

Workflow: Existing non-virtualized project

1. Switch to project directory

   cd <project_path>

2. Freeze requirements based on imports (if needed)

   pipreqs .

3. Set Python version required by the project

   pyenv shell 2.7-dev

4. Create virtual environment (if needed)

   mkvirtualenv -r <requirements_file_path> <virtualenv_name>

5. Bind an existing virtualenv to an existing project

   setvirtualenvproject <virtualenv_path> <project_path>

   or just

   setvirtualenvproject

   if environment activated and PWD is a project root directory
6. Working on a project ...
7. Exit environment

   source deactivate

Workflow: Temporary environment

1. Set Python version for the project

   pyenv shell 2.7-dev

2. Create temporary virtual environment

   mktmpenv

3. Working ...
4. Exit environment (environment folder will be deleted on deactivation)

   source deactivate