{
  description = "A development shell for Python 3.12 with Pandas and Requests.";

  # Define the inputs (dependencies) for the flake
  inputs = {
    # Pin nixpkgs to a specific channel (e.g., nixos-unstable) for a reproducible environment
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  };

  # Define the outputs (what the flake provides)
  outputs = { self, nixpkgs, ... }@inputs:
    let
      # Define the systems this flake supports
      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];

      # Create a function that maps the supported systems to the nixpkgs instance
      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;

      # Get the packages set for all systems
      pkgs = forAllSystems (system: import nixpkgs { inherit system; });

    in
    {
      # Define the development shells
      devShells = forAllSystems (system: {
        default = pkgs.${system}.mkShell {
          name = "python-312-dev-shell";

          # 1. Select the specific Python interpreter (Python 3.12)
          # 2. Use .withPackages to create an environment that includes the specified libraries
          packages = [
            (pkgs.${system}.python312.withPackages (python-pkgs: with python-pkgs; [
              # Python libraries
              pip
              virtualenv
              requests
              pandas 
              types-requests
              # Optional: Add other helpful dev tools outside of the python-pkgs set if needed
              # (e.g., git, pre-commit, bash-completion)
            ]))
          ];

          # Optional: Define environment variables for the shell
          shellHook = ''
            echo "🐍 Entering Python 3.12 development environment."
            echo "   (pip and Requests are available)"
            python --version
          '';
        };
      });
    };
}