Fix some PEP8 warning.

fluid/adversarial/advbox/__init__.py

@@ -2,6 +2,6 @@
    A set of tools for generating adversarial example on paddle platform
 """
 
-from . import attacks  # type: ignore # noqa: F401
-from . import models  # type: ignore # noqa: F401
-from .adversary import Adversary  # noqa: F401
+from . import attacks
+from . import models
+from .adversary import Adversary

fluid/adversarial/advbox/attacks/base.py

@@ -29,18 +29,19 @@ class Attack(object):
 
         Args:
         adversary(object): The adversary object.
-        **kwargs: Other params.
+        **kwargs: Other named arguments.
         """
         self._preprocess(adversary)
         return self._apply(adversary, **kwargs)
 
     @abstractmethod
-    def _apply(self, adversary):
+    def _apply(self, adversary, **kwargs):
         """
         Search an adversarial example.
 
         Args:
         adversary(object): The adversary object.
+        **kwargs: Other named arguments.
         """
         raise NotImplementedError
 
@@ -65,6 +66,6 @@ class Attack(object):
 
         logging.info('adversary:\noriginal_label: {}'
                      '\n          target_lable: {}'
-                     '\n          is_targeted_attack: {}'.format(
-                         adversary.original_label, adversary.target_label,
-                         adversary.is_targeted_attack))
+                     '\n          is_targeted_attack: {}'
+                     ''.format(adversary.original_label, adversary.target_label,
+                               adversary.is_targeted_attack))

fluid/adversarial/advbox/attacks/gradientsign.py

@@ -20,6 +20,14 @@ class GradientSignAttack(Attack):
     """
 
     def _apply(self, adversary, epsilons=1000):
+        """
+          Apply the gradient sign attack.
+          Args:
+              adversary(Adversary): The Adversary object.
+              epsilons(list|tuple|int): The epsilon (input variation parameter).
+          Return:
+              adversary: The Adversary object.
+          """
         assert adversary is not None
 
         if not isinstance(epsilons, Iterable):

fluid/adversarial/advbox/attacks/iterator_gradientsign.py

@@ -21,11 +21,11 @@ class IteratorGradientSignAttack(Attack):
         """
         Apply the iterative gradient sign attack.
         Args:
-            adversary(object): The image and label tuple list of one element.
+            adversary(Adversary): The Adversary object.
             epsilons(list|tuple|int): The epsilon (input variation parameter).
             steps(int): The number of iterator steps.
         Return:
-            numpy.ndarray: The adversarail sample generated by the algorithm.
+            adversary(Adversary): The Adversary object.
         """
 
         if not isinstance(epsilons, Iterable):

fluid/adversarial/advbox/models/__init__.py

 """
 Paddle model for target of attack
 """
-from .base import Model  # noqa: F401
-from .paddle import PaddleModel  # noqa: F401
+from .base import Model
+from .paddle import PaddleModel

fluid/adversarial/advbox/models/paddle.py

+"""
+Paddle model
+"""
 from __future__ import absolute_import
 
 import paddle.v2.fluid as fluid