add basic python

python/flake.nix

@@ -0,0 +1,39 @@
+{
+  description = "Python spaghetti from samw";
+
+  inputs = {
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      treefmt-nix,
+      ...
+    }:
+    let
+      systems = [
+        "aarch64-darwin"
+        "x86_64-linux"
+      ];
+      eachSystem = f: nixpkgs.lib.genAttrs systems (system: f nixpkgs.legacyPackages.${system});
+      treefmtEval = eachSystem (pkgs: treefmt-nix.lib.evalModule pkgs ./treefmt.nix);
+    in
+    {
+      devShells = eachSystem (pkgs: {
+        default = pkgs.mkShellNoCC {
+          buildInputs = with pkgs; [
+            uv
+            ty
+          ];
+        };
+      });
+      formatter = eachSystem (pkgs: treefmtEval.${pkgs.stdenv.hostPlatform.system}.config.build.wrapper);
+      # for `nix flake check`
+      checks = eachSystem (pkgs: {
+        formatting = treefmtEval.${pkgs.system}.config.build.check self;
+      });
+    };
+}

python/treefmt.nix

@@ -0,0 +1,5 @@
+{ pkgs, ... }: {
+  projectRootFile = "flake.nix";
+  programs.nixfmt.enable = true;
+  programs.ruff.enable = true;
+}