Update util.py

util.py

@@ -13,18 +13,18 @@ def get_questions(file_path):
     return result
 
 def read_file(file_path):
+    df = None
+
     ext = os.path.splitext(file_path)[1].lower()
 
-    result = ""
-    
     if ext == ".csv":
-        result = pd.read_csv(file_path)
+        df = pd.read_csv(file_path)
     elif ext in (".xls", ".xlsx"):
-        result = pd.read_excel(file_path)
+        df = pd.read_excel(file_path)
     elif ext in (".json", ".jsonl"):
-        result = pd.read_json(file_path)
+        df = pd.read_json(file_path)
 
-    return result.to_string()
+    return "" if df is None else df.to_string()
 
 def get_final_answer(model, question, answer):
     prompt_template = """