diff --git a/colossalai/engine/gradient_handler/__init__.py b/colossalai/engine/gradient_handler/__init__.py
index b6503b778..6177da69b 100644
--- a/colossalai/engine/gradient_handler/__init__.py
+++ b/colossalai/engine/gradient_handler/__init__.py
@@ -6,7 +6,7 @@ from ._pipeline_parallel_gradient_handler import PipelineSharedModuleGradientHan
 from ._moe_gradient_handler import MoeGradientHandler
 from ._sequence_parallel_gradient_handler import SequenceParallelGradientHandler
 
-
-__all__ = ['BaseGradientHandler', 'DataParallelGradientHandler',
-           'ZeROGradientHandler', 'PipelineSharedModuleGradientHandler',
-           'MoeGradientHandler', 'SequenceParallelGradientHandler']
\ No newline at end of file
+__all__ = [
+    'BaseGradientHandler', 'DataParallelGradientHandler', 'ZeROGradientHandler', 'PipelineSharedModuleGradientHandler',
+    'MoeGradientHandler', 'SequenceParallelGradientHandler'
+]