Nix Recipe: Setup Python

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.