diff --git a/convlab2/dst/dstc9/utils.py b/convlab2/dst/dstc9/utils.py
index 13d54b7f2e9141e462ca557b7a5d2802f0c294e4..b378fd2e79486c0c9936f887a307ca1746e4e1aa 100644
--- a/convlab2/dst/dstc9/utils.py
+++ b/convlab2/dst/dstc9/utils.py
@@ -5,8 +5,13 @@ import zipfile
 from convlab2 import DATA_ROOT
 
 
+def get_subdir(subtask):
+    subdir = 'multiwoz_zh' if subtask == 'multiwoz' else 'crosswoz_en'
+    return subdir
+
+
 def prepare_data(subtask, split, data_root=DATA_ROOT):
-    data_dir = os.path.join(data_root, 'multiwoz_zh' if subtask == 'multiwoz' else 'crosswoz_en')
+    data_dir = os.path.join(data_root, get_subdir(subtask))
     zip_filename = os.path.join(data_dir, f'{split}.json.zip')
     test_data = json.load(zipfile.ZipFile(zip_filename).open(f'{split}.json'))
     data = {}
@@ -131,8 +136,3 @@ def eval_states(gt, pred, subtask):
             'f1': f1,
         }
     }
-
-
-def get_subdir(subtask):
-    subdir = 'multiwoz_zh' if subtask == 'multiwoz' else 'crosswoz_en'
-    return subdir