Create Nix expressions for python packages

wheels.nix

Extracted from python branch from chaoflow's work.

https://github.com/chaoflow/nixpkgs/tree/python/pkgs/development/python-wheels

pyEnv = python.buildEnv {
  buildInput = [];
  propagatedBuildInput
};

python

A tool that generates nix expressions for your python packages, so you don't have to.

To simply create development environment for you python project you simply do::

Using setuptools:

# not yet working
% pypi2nix setup.py

Using requirements.txt (created by pip freeze):

# working but only if you provide full set of dependencies
# eg. pip freeze will give you this
% pypi2nix requirements.txt

Using zc.buildout:

# not yet working
% pypi2nix buildout.cfg

To step into development environment:

% nix-shell

How pypi2nix works internally look at Design section of this document.

Installation

Install pypi2nix by running::

% nix-env -i pypi2nix

Contribute

• Issue Tracker: https://github.com/NixOS/pypi2nix
• Source Code: https://github.com/NixOS/pypi2nix

To develop pypi2nix::

% git clone git://github.com/NixOS/pypi2nix.git
% nix-shell

To build pypi2nix binary:

% make clear install DESTDIR=./out

As example you can try generate Sentry's delependencies:

% cd examples
% ./../out/pypi2nix sentry.nix --nix-path=nixpkgs=/path/to/nixpkgs-chaoflows-python-branch

Code away!

If you are having issues, please let us know via issue tracker.

Design

% pypi2nix <input>

Above command will first generate generated.json file which includes md5 hashes for all python packages we need to package. We used JSON format here because its easy to read from nix and python, and this step is used to cache all lookups to pypi on any subsequent calls.

Then it will use it to build python wheels inside /nix/store and read all metadata (description, homepage, license, requires, ...) and create generated.nix.

Last piece to connect everything together is default.nix. This file is going to be generated and if file already exists it will ask you if you want to override it.

And that's it. Looks complicated, but that's just the way python packaging is.

You should read more about nix-shell and how to use it with default.nix to get most out of python development with nix.

License