Update app.py

app.py

@@ -74,7 +74,9 @@ def flip_video_horizontally(video_path):
 
     cap.release()
     out.release()
-
+    
+    print(video_path, os.path.exists(video_path))
+    print(temp_output_path, os.path.exists(temp_output_path))
     os.replace(temp_output_path, video_path)
     print(f"Finished flipping video：{video_path}")