fix zip() problem for python3.5
@@ -1404,7 +1404,7 @@ class LBFGS_attack(object):
# set the box constraints for the optimization function
clip_min = self.clip_min*np.ones(oimgs.shape[:])
clip_max = self.clip_max*np.ones(oimgs.shape[:])
- clip_bound = zip(clip_min.flatten(), clip_max.flatten())
+ clip_bound = list(zip(clip_min.flatten(), clip_max.flatten()))
# placeholders for the best l2 and instance attack found so far
o_bestl2 = [1e10] * self.batch_size
