diff --git a/erniebot-agent/applications/erniebot_researcher/tools/preprocessing.py b/erniebot-agent/applications/erniebot_researcher/tools/preprocessing.py
index ff3c2076..a51c7bd1 100644
--- a/erniebot-agent/applications/erniebot_researcher/tools/preprocessing.py
+++ b/erniebot-agent/applications/erniebot_researcher/tools/preprocessing.py
@@ -14,7 +14,7 @@
     SimpleDirectoryReader,
     StorageContext,
     VectorStoreIndex,
-    load_index_from_storage
+    load_index_from_storage,
 )
 from llama_index.node_parser import SentenceSplitter
 from llama_index.vector_stores.faiss import FaissVectorStore