add nix

.envrc

@@ -0,0 +1 @@
+use flake

flake.nix

@@ -0,0 +1,20 @@
+{
+  description = "A Nix-flake-based Python development environment";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  outputs = { self, nixpkgs }:
+    let
+      forEachSupportedSystem = f: nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed (system: f {
+        pkgs = import nixpkgs { inherit system; };
+      });
+    in
+    {
+      devShells = forEachSupportedSystem ({ pkgs }: {
+        default = pkgs.mkShell {
+          packages = with pkgs; [ python313 virtualenv libffi libsodium jetbrains.pycharm-community ] ++
+            (with pkgs.python313Packages; [ pip virtualenv ]);
+        };
+      });
+    };
+}