This is a nix recipe for building and running python in a virtual nix environment.

  • Create shell.nix with following:

    let
  nixpkgs = import (builtins.fetchTarball https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz) {
    overlays = [];
    config = {};
  };

in
  with nixpkgs;

  stdenv.mkDerivation {
    name = "python-env";

    nativeBuildInputs = [
      zsh
      vim
      python37
      python37Packages.pip
      python37Packages.virtualenv
    ];

    # ENV variables
    PROJDIR = "${toString ./.}";

    # Post Shell Hook
    shellHook = ''
      echo "Using ${python37.name}"

      [ ! -d '$PROJDIR/python-dev' ] && virtualenv python-dev && echo "SETUP python-dev: DONE"
      source python-dev/bin/activate
      # python -m pip install -r requirements.txt
    '';
  }

    Note:

    • Here, the nix packages are installed from 20.03 release.
    • virtualenv is installed and activated, and python requirements are installed in this environment (via requirements.txt file).

  • Run nix-shell --pure shell.nix to build and start using python-3.7 in your virtual environment.