with import <nixpkgs> {};

stdenv.mkDerivation {
  name = "myPythonEnv";
  buildInputs = with pkgs; [
    python36Full
    python36Packages.virtualenv
    python36Packages.pip
  ];
  src = null;
  shellHook = ''
    # set SOURCE_DATE_EPOCH so that we can use python wheels
    SOURCE_DATE_EPOCH=$(date +%s)
    virtualenv --no-setuptools venv
    export PATH=$PWD/venv/bin:$PATH
    if [ -s requirements.txt ]; then
      pip install -r requirements.txt
    fi
  '';
}