diff --git a/rag/flow/tokenizer/tokenizer.py b/rag/flow/tokenizer/tokenizer.py
index 6b77f4a84..6b66dcff3 100644
--- a/rag/flow/tokenizer/tokenizer.py
+++ b/rag/flow/tokenizer/tokenizer.py
@@ -65,6 +65,7 @@ class Tokenizer(ProcessBase):
             txt = ""
             if isinstance(self._param.fields, str):
                 self._param.fields=[self._param.fields]
+                
             for f in self._param.fields:
                 if f not in c:
                     continue