diff --git a/examples/face_adversarial_attack/example/loss_design.py b/examples/face_adversarial_attack/example/loss_design.py
index fb63dc4..2e70955 100644
--- a/examples/face_adversarial_attack/example/loss_design.py
+++ b/examples/face_adversarial_attack/example/loss_design.py
@@ -34,7 +34,7 @@ class MyTrainOneStepCell(nn.TrainOneStepCell):
     """
 
     def __init__(self, network, optimizer, sens=1.0):
-        super(MyTrainOneStepCell, self).__init__(network, optimizer,sens)
+        super(MyTrainOneStepCell, self).__init__(network, optimizer, sens)
         self.grad = ops.composite.GradOperation(get_all=True, sens_param=False)
 
     def construct(self, *inputs):