diff --git a/demo/mnist/light_mnist.py b/demo/mnist/light_mnist.py
index d796a3cc06777d2f6dc3489140519b85019862a5..33409054357d2f0c6a765b3ab3164eb2e584467e 100644
--- a/demo/mnist/light_mnist.py
+++ b/demo/mnist/light_mnist.py
@@ -35,6 +35,7 @@ data_size = 1 * 28 * 28
 label_size = 10
 img = data_layer(name='pixel', size=data_size)
 
+
 # light cnn
 # A shallower cnn model: [CNN, BN, ReLU, Max-Pooling] x4 + FC x1
 # Easier to train for mnist dataset and quite efficient