diff --git a/adversarial/advbox/attacks/base.py b/adversarial/advbox/attacks/base.py
index dab1dbbeb0270d303dbec1bd0b28a43e9d26f075..2058e3cfeb17dfce2713c38748f2a628e83a69f1 100644
--- a/adversarial/advbox/attacks/base.py
+++ b/adversarial/advbox/attacks/base.py
@@ -1,11 +1,7 @@
 """
 The base model of the model.
 """
-from abc import ABCMeta
-#from advbox.base import Model
-import abc
-
-abstractmethod = abc.abstractmethod
+from abc import ABCMeta, abstractmethod
 
 
 class Attack(object):
diff --git a/adversarial/advbox/attacks/gradientsign.py b/adversarial/advbox/attacks/gradientsign.py
index 37fbdb11328a66a37ec58621ad92dbd3db6d58ed..dff518811efbbab6b5546380378115e2589398b7 100644
--- a/adversarial/advbox/attacks/gradientsign.py
+++ b/adversarial/advbox/attacks/gradientsign.py
@@ -30,9 +30,7 @@ class GradientSignAttack(Attack):
                 gradient_sign.shape) + epsilon * gradient_sign
             adv_img = np.clip(adv_img, min_, max_)
             adv_label = np.argmax(self.model.predict([(adv_img, 0)]))
-            #print("pre_label="+str(pre_label)+ " adv_label="+str(adv_label))
             if pre_label != adv_label:
-                #print(epsilon, pre_label, adv_label)
                 return adv_img