Nix Shell Python virtualenv

shell.nix

{ stdenv ? import <nixpkgs> {} }:

let

  inherit (stdenv) pkgs mkShell;
  inherit (stdenv.lib) flatten;

in

mkShell rec {
  name = "venv";
  buildInputs =
    with pkgs;
    with python37Packages; [
      python3
      pip
      virtualen
    ];

  shellHook = /* sh */ ''
    virtualenv --no-setuptools .venv
    source ./.venv/bin/activate
    unset PYTHONPATH
  '';
}