let
  pkgs = import <nixpkgs> {
    overlays = [ ];
  };
in
pkgs.mkShell {
  buildInputs = with pkgs; [
    python3
  ];
  shellHook = ''
    if [ ! -d .venv ]; then
      python -m venv .venv
    fi
    source .venv/bin/activate
  '';
}