Add flake as venv replacement

flake.lock

@@ -0,0 +1,24 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1681737997,
+        "narHash": "sha256-pHhjgsIkRMu80LmVe8QoKIZB6VZGRRxFmIvsC5S89k4=",
+        "path": "/nix/store/9gyra3774fp9bdzchrvq2v4y9nia0pc3-source",
+        "rev": "f00994e78cd39e6fc966f0c4103f908e63284780",
+        "type": "path"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,15 @@
+{
+  outputs = { self, nixpkgs }:
+    let forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
+    in {
+      devShells = forAllSystems (system:
+        let
+          pkgs = import nixpkgs { inherit system; };
+          pythonPkgs = ps: with ps; [ requests ];
+        in
+        {
+          default = (pkgs.python3.withPackages pythonPkgs).env;
+        }
+      );
+    };
+}