Update app.py

app.py

@@ -246,4 +246,7 @@ def main():
     root = tk.Tk()
     app = App(root)
     print(f"===== Application Startup at {datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')} =====")
-    app.run()
+    app.run()
+
+if __name__ == "__main__":
+    main()