Update util.py

util.py

@@ -17,11 +17,11 @@ def read_file(file_path):
 
     result = ""
     
-    if ext == '.csv':
+    if ext == ".csv":
         result = pd.read_csv(file_path)
-    elif ext in ('.xls', '.xlsx'):
+    elif ext in (".xls", ".xlsx"):
         result = pd.read_excel(file_path)
-    elif ext in ('.json', '.jsonl'):
+    elif ext in (".json", ".jsonl"):
         result = pd.read_json(file_path)
 
     return result