add template for python requirements.txt projects

templates/python/flake.nix

@@ -0,0 +1,20 @@
+{
+  description = "Python pip flake";
+
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs";
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        pythonEnv = pkgs.python310.withPackages (pypi:
+          with pypi;
+          [
+            # Add requirements here
+            requests
+          ]);
+      in {
+        devShells.default = pkgs.mkShell { buildInputs = [ pythonEnv ]; };
+      });
+}