add flake file

flake.lock

+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1642961095,
+        "narHash": "sha256-RLatktZmvwFBOyqdoIk4qdS4OGKB7aKIvvs4ZP2L8D8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "604c44137d97b5111be1ca5c0d97f6e24fbc5c2c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-21.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

+{
+  description = "wl-togglescreens script for toggle screens on Wayland";
+
+  inputs.nixpkgs.url = github:NixOS/nixpkgs/nixos-21.11;
+
+  outputs = { self, nixpkgs }: {
+
+    defaultPackage.x86_64-linux =
+      # Notice the reference to nixpkgs here.
+      with import nixpkgs { system = "x86_64-linux"; };
+      stdenv.mkDerivation {
+        name = "wl-togglescreens";
+	version = "0.1";
+        src = self;
+
+	buildInputs = [ 
+	  python3
+	];
+
+	nativeBuildInputs = with python3Packages; [
+	  wrapPython
+	];
+
+	dontBuild = true;
+
+        installPhase = ''
+	  install -vD main.py $out/bin/wl-togglescreens
+	'';
+
+	postFixup = "
+	  wrapPythonPrograms
+	";
+      };
+
+  };
+}

main.py

@@ -13,10 +13,11 @@ class Screen:
 
     @state.setter
     def state(self, value):
-        if self._state != None and value:
-            subprocess.run(['wlr-randr', '--output', self.name, '--on'])
-        else:
-            subprocess.run(['wlr-randr', '--output', self.name, '--off'])
+        if self._state != None:
+            if value:
+                subprocess.run(['wlr-randr', '--output', self.name, '--on'])
+            else:
+                subprocess.run(['wlr-randr', '--output', self.name, '--off'])
         self._state = value
 
 class wlScreens:
@@ -40,7 +41,12 @@ class wlScreens:
                 screen.state = False
 
     def toggleModes(self):
-        if (len(self.screens) == 2):
+        if (len(self.screens) == 1):
+            if (self.screens[0].state == True):
+                self.screens[0].state = False
+            else:
+                self.screens[0].state = True
+        elif (len(self.screens) == 2):
             if (self.screens[0].state == True and self.screens[1].state == True):
                 self.screens[0].state = False
             elif (self.screens[0].state == False and self.screens[1].state == True):
@@ -48,11 +54,6 @@ class wlScreens:
                 self.screens[0].state = True
             elif (self.screens[0].state == True and self.screens[1].state == False):
                 self.screens[1].state = True
-        if (len(self.screens) == 1):
-            if (self.screens[0].state == True):
-                self.screens[0].state = False
-            else:
-                self.screens[0].state = True
 
     def __len__(self):
         return len(self.screens)