{
  description = "A Python project";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-24.05";
  };

  outputs = {
    self,
    nixpkgs,
  }: let
    system = "x86_64-linux";
    pkgs = import nixpkgs {inherit system;};

    my-python = pkgs.python3.withPackages (ps: [ps.numpy]);
  in {
    formatter.${system} = pkgs.alejandra;

    devShells.${system} = {
      default = self.devShells.${system}.foo;
      foo = pkgs.mkShell {
        packages = with pkgs; [
          my-python
        ];
      };
    };

    packages.${system} = {
      default = self.packages.${system}.hello;
      hello = pkgs.writeShellScriptBin "hello" ''
        ${pkgs.python3}/bin/python ${./main.py}
      '';
    };
  };
}