add file not found

app.py

@@ -3,6 +3,8 @@ import pandas as pd
 import random
 from collections import defaultdict
 import json
+import os 
+import sys
 
 css = """
 .rtl{
@@ -34,6 +36,11 @@ def process_rankings(user_rankings):
         model_rankings[model][f'{rank}{rank_suffix}'] += 1  # Using the correct suffix based on the rank
 
     file_path = 'users_ranking.txt'
+    if not os.path.exists(file_path):
+    # If the file path does not exist, print an error message and exit the script
+        print(f"Error: The file path '{file_path}' does not exist.")
+        sys.exit(1)  # Exit the script with an error code (1 is a common choice for a general error)
+
     with open(file_path, 'a') as file:
         model_rankings_dict = dict(model_rankings)
         json.dump(model_rankings_dict, file)