yen

The last Python environment manager you'll ever need.

We're finally putting an end to this XKCD.

So what can yen do?

• Get any Python version running instantly with just 1 command:

  $ python
  'python': command not found
  
  $ yen exec --python 3.12
  Downloading 3.12.3 ━━━━━━━━━━━━━━━━━━━━━━━━━ 100.0% • 17.4/17.4 MB • 29.1 MB/s
  Python 3.12.3 (main, Apr 15 2024, 17:43:11) [Clang 17.0.6 ] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  >>> exit()
  
  $ yen exec --python 3.12  # Cached for subsequent uses:
  Python 3.12.3 (main, Apr 15 2024, 17:43:11) [Clang 17.0.6 ] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  >>>

  Works on Windows, MacOS and Linux (libc and musl), on Intel and ARM chips.

• Instant venv creation: Thanks to microvenv, yen can create virtual environments much faster than the builtin venv module:

  $ yen create venv -p 3.9
  Created venv with Python 3.9.18 ✨
  
  $ source venv/bin/activate
  
  (venv) $ python --version
  Python 3.9.18

  NOTE: It's not that fast right now as I found a bug. Working on it.

• Zero dependencies: No need to have Python installed, no need to look into apt, homebrew etc., just run one shell command to get yen set up locally.

• Python script management: Never run pip install to get a tool like ruff, awscli etc. in the global Python environment ever again.

Essentially, yen lets you replace various Python environment management tools such as pyenv, pipx and virtualenv, with a single static binary.

Running Python code on any machine has never been this easy.

Installation

Get yen by running the following command:

• MacOS / Linux:

  curl -L yen.tushar.lol/install.sh | sh

• Windows:

  Using cmd:

  curl -L yen.tushar.lol/install.bat -o yen-install.bat
  yen-install.bat

  or using Powershell:

  curl yen.tushar.lol/install.ps1 | Invoke-Expression

or if you prefer, get it via pip:

pip install yen

or pipx:

pipx run yen

Yeah, if you already have yen, you can do yen run yen and that works. But don't do that.

You can also grab the binary from GitHub releases.

Usage

$ yen list
Available Pythons:
3.12.3
3.11.9
3.10.14
3.9.19
3.8.19

$ yen create venv -p 3.12
Downloading 3.12.3 ━━━━━━━━━━━━━━━━━━━━━━━━━ 100.0% • 17.4/17.4 MB • 12.4 MB/s
Created venv with Python 3.12.3 ✨

$ yen install meowsay
Installed package meowsay with Python 3.12.3 ✨

$ meowsay hello!
 ________
< hello! >
 --------
        \      |\---/|
         \     | ,_, |
                \_`_/-..----.
             ___/ `   ' ,\"\"+ \  sk
            (__...'   __\    |`.___.';
              (_,...'(_,.`__)/'.....+

$ yen run --python 3.9 wttr
Weather report: Milano, Italy

     \  /       Partly cloudy
   _ /"".-.     20 °C
     \_(   ).   ↑ 4 km/h
     /(___(__)  10 km
                0.0 mm

$ wttr paris
Weather report: paris

      \   /     Sunny
       .-.      +22(25) °C
    ― (   ) ―   ↓ 7 km/h
       `-’      10 km
      /   \     0.0 mm

By default the Pythons will be downloaded in ~/.yen_pythons. You can change this location by setting the YEN_PYTHONS_PATH environment variable.

Local Development / Testing

• Run yen create venv and venv/bin/activate

• Run pip install -r requirements-dev.txt to do an editable install

• Verify that you're now pointing at the correct yen:

  $ which yen
  /home/your_name/code/yen/venv/bin/yen

• Run pytest to run tests

To run Rust tests:

• Compile the rust project: cd yen-rs && cargo build
• Run export YEN_RUST_PATH=./yen-rs/target/debug/yen-rs
• Run pytest, and ensure that number of tests ran has doubled.

microvenv.py and userpath.pyz

These two files are used by yen and downloaded by the yen install script.

• microvenv.py is just this file renamed.
• userpath.pyz is created by running ./build-standalone.sh in this fork of userpath.

Type Checking

Run mypy .

Create and upload a package to PyPI

Make sure to bump the version in setup.cfg.

Then run the following commands:

pip install setuptools wheel twine
rm -rf build dist
python setup.py sdist bdist_wheel

Then upload it to PyPI using twine:

twine upload dist/*