Added a script that list least important nixos generations

flake.nix

@@ -0,0 +1,18 @@
+{
+  description = "A very basic flake";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        python-env = pkgs.python3.withPackages
+          (ps: with ps; [ jupyter requests pandas matplotlib click ]);
+      in {
+        devShells.default = pkgs.mkShell { buildInputs = [ python-env ]; };
+      });
+}