diff --git a/api/configs/feature/__init__.py b/api/configs/feature/__init__.py
index f48c074ac8c1cc..ce9f8f2725dce9 100644
--- a/api/configs/feature/__init__.py
+++ b/api/configs/feature/__init__.py
@@ -619,13 +619,10 @@ class DataSetConfig(BaseSettings):
     PLAN_SANDBOX_CLEAN_MESSAGE_DAY_SETTING: PositiveInt = Field(
         description="Interval in days for message cleanup operations - plan: sandbox",
         default=30,
-    ) 
-    
-    RETRIEVAL_TOP_N: Optional[PositiveInt] = Field(
-        description="number of retrieval top_n", 
-        default=None
     )
 
+    RETRIEVAL_TOP_N: Optional[PositiveInt] = Field(description="number of retrieval top_n", default=None)
+
 
 class WorkspaceConfig(BaseSettings):
     """
diff --git a/api/core/rag/datasource/retrieval_service.py b/api/core/rag/datasource/retrieval_service.py
index dbd8fb7cd76073..759166da4c4be8 100644
--- a/api/core/rag/datasource/retrieval_service.py
+++ b/api/core/rag/datasource/retrieval_service.py
@@ -106,16 +106,15 @@ def retrieve(
             exception_message = ";\n".join(exceptions)
             raise Exception(exception_message)
 
-
         if retrieval_method == RetrievalMethod.HYBRID_SEARCH.value:
             data_post_processor = DataPostProcessor(
                 str(dataset.tenant_id), reranking_mode, reranking_model, weights, False
             )
             all_documents = data_post_processor.invoke(
-                query=query, 
-                documents=all_documents, 
-                score_threshold=score_threshold, 
-                top_n=DifyConfig.RETRIEVAL_TOP_N if DifyConfig.RETRIEVAL_TOP_N else top_k
+                query=query,
+                documents=all_documents,
+                score_threshold=score_threshold,
+                top_n=DifyConfig.RETRIEVAL_TOP_N or top_k,
             )
 
         return all_documents
@@ -184,10 +183,10 @@ def embedding_search(
                         )
                         all_documents.extend(
                             data_post_processor.invoke(
-                                query=query, 
-                                documents=documents, 
-                                score_threshold=score_threshold, 
-                                top_n=DifyConfig.RETRIEVAL_TOP_N if DifyConfig.RETRIEVAL_TOP_N else len(documents)
+                                query=query,
+                                documents=documents,
+                                score_threshold=score_threshold,
+                                top_n=DifyConfig.RETRIEVAL_TOP_N or len(documents),
                             )
                         )
                     else:
@@ -229,10 +228,10 @@ def full_text_index_search(
                         )
                         all_documents.extend(
                             data_post_processor.invoke(
-                                query=query, 
-                                documents=documents, 
-                                score_threshold=score_threshold, 
-                                top_n=DifyConfig.RETRIEVAL_TOP_N if DifyConfig.RETRIEVAL_TOP_N else len(documents)
+                                query=query,
+                                documents=documents,
+                                score_threshold=score_threshold,
+                                top_n=DifyConfig.RETRIEVAL_TOP_N or len(documents),
                             )
                         )
                     else: