{
  inputs.nixpkgs.url = "github:nixos/nixpkgs";
  outputs = { self, nixpkgs }:
    let
      pkgs = nixpkgs.legacyPackages.x86_64-linux;
      my-python = pkgs.python3;
      tkcalendar = pkgs.python3Packages.buildPythonPackage rec {
        pname = "tkcalendar";
        version = "1.6.1";

        src = pkgs.fetchFromGitHub {
          owner = "j4321";
          repo = "tkcalendar";
          rev = "v${version}";
          sha256 = "Z5Sg1kT9VS0WNyJ3nXXhKbzL1VEXwkbF4bV8OwprYfE=";
        };

        propagatedBuildInputs = [
          pkgs.python310Packages.tkinter
          pkgs.python310Packages.babel
        ];

        doCheck = false;
        pythonImportsCheck = [ "tkcalendar" ];
      };

      calcure = pkgs.python3Packages.buildPythonApplication rec {
        pname = "calcure";
        version = "2.6";

        src = pkgs.fetchFromGitHub {
          owner = "anufrievroman";
          repo = "calcure";
          rev = "${version}";
          sha256 = "VvK8kLQd8JKaLQoxtMbweOKnR9nKMEnlj0103DeLXRI=";
        };

        propagatedBuildInputs = [
          pkgs.python310Packages.holidays
          pkgs.python310Packages.jdatetime
        ];

        # doCheck = false;
      };

      ttkbootstrap = pkgs.python3Packages.buildPythonPackage rec {
        pname = "ttkbootstrap";
        version = "1.10.0";

        src = pkgs.fetchFromGitHub {
          owner = "israel-dryer";
          repo = "ttkbootstrap";
          rev = "v${version}";
          sha256 = "tWzpgNv54uuB9hntO/iek6zrH4RWk9MrREXdwpDRDPw=";
        };

        propagatedBuildInputs = [
          pkgs.python310Packages.pillow
          pkgs.python310Packages.tkinter
        ];

        # doCheck = false;
        pythonImportsCheck = [ "ttkbootstrap" ];
      };

      python-with-my-packages = my-python.withPackages (p: with p; [
        tkinter
        tkcalendar
        ttkbootstrap
        ical
      ]);
    in
    {
      packages.tkcalendar = pkgs.callPackage tkcalendar { };
      packages.ttkbootsrap = pkgs.callPackage ttkbootstrap { };
      packages.calcure = pkgs.callPackage calcure { };
      devShell.x86_64-linux = pkgs.mkShell {
        buildInputs = with pkgs; [
          yad
          python-with-my-packages
          calcure
        ];
      };
    };
}