pyenv-virtualenv cheat sheet

Instructions to nuke your previous anaconda installation

Lora Johns wrote the Mac version. This is a close copy translated for Linux (specifically, my Mint 19.2 system).

1. Install and run the Anaconda uninstaller

conda install anaconda-clean && anaconda-clean --yes

1. Find leftover directories and remove them (with rm -rf, or more conservatively)

grep -iR "Anaconda3" ~

1. Check your .bashrc, .bash_profile, or equivalent login profile and delete the conda init lines added by “Anaconda.3 xxxx.xx installer” and anything anaconda-related in your path.

2. Restart your shell.

source ~/.bashrc

Install pyenv and pyenv-virtualenv (Linux instructions)

1. Install pyenv and pyenv-virtualenv from source.

You can clone the GitHub repos (instructions in their READMEs), but running pyenv-installer may be more convenient.

curl https://pyenv.run | bash

1. Configure pyenv and pyenv-virtualenv

echo 'export PYENV_ROOT= "$HOME/.pyenv"' >> ~/.bashrc
echo 'export PATH=$PYENV_ROOT/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(pyenv init -)"' >> ~/.bashrc
echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bashrc

1. Install python versions with pyenv

• get a list of options: pyenv install --list
• remove a version: pyenv uninstall
• install a version: pyenv install

1. Set your global and local pythons

• set your global python: pyenv global 3.x.x
• set your local (project) python–important for venv switching! pyenv local 3.x.x
• set a version for the current shell: pyenv shell 3.x.x
• use a one-off python module or command: pyenv exec python [-m, -c]

1. Create and activate virtual environments

• set local python: pyenv local 3.x.x or pyenv local anaconda xxxx.xx
• make a venv: pyenv virtualenv 3.x.x name-of-your-new-venv
• set and activate: pyenv local name-of-your-new-venv && pyenv activate name-of-your-new-venv
• if you used conda: conda activate your-new-conda-env

Optional helpful pyenv management

• To prevent old Python 2 habits creeping in by mistake, alias virtualenv to pyenv virtualenv

echo 'alias virtualenv="pyenv virtualenv"' >> ~/.bashrc

• Delete virtual envs created with pyenv: pyenv uninstall venv-name or rm -rf venv-directory

Set up Visual Studio Code for Python and Jupyter

1. Get VSCode. I used snap: sudo snap install --classic code, but it’s probably easier to download and run the deb package or the equivalent for other distributions.
2. Install and enable the Python extension
3. In VSCode, open the command palette (command+shift+P) and configure the Terminal options to integrate with the system terminal (e.g., zsh and iTerm2)

• vscode will now inherit your venvs and automatically switch them with pyenv virtualenv

1. In VSCode, open the command palette (command+shift+P) and choose Shell command: Install 'code' command in path

• now you can open files and directories from the command line with code ., code file.py, code. /path/to/stuff/, etc.

1. Launch a project directory with anaconda or jupyter enabled with code /path/to/project.
2. command+shift+P Python: Create New Blank Jupyter Notebook (or open an existing one, if you like)
3. Convert notebooks to .py scripts with one click

More VSCode fun

• use github integration (pull, diff, merge, push) directly from the editor
• install themes with syntax highlighting, code linters, testing, and more tools
• polyglot code support!