Apply isort rules

34 files changed, 272 insertions, 136 deletions

diff --git a/setup.cfg b/setup.cfg
index 3aa3064..5d7fd75 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,3 +19,14 @@ ignore =
     docs/_build/html/_sources/*
     docs/_build/doctest/*
     docs/_build/html/_sources/api/*
+
+[isort]
+force_single_line = True
+combine_as_imports = True
+sections = FUTURE,STDLIB,THIRDPARTY,ZOPE,FIRSTPARTY,LOCALFOLDER
+known_third_party = six, docutils, pkg_resources
+known_zope =
+known_first_party =
+default_section = ZOPE
+line_length = 79
+lines_after_imports = 2
diff --git a/setup.py b/setup.py
index bd750ee..cd3e62e 100644
--- a/setup.py
+++ b/setup.py
@@ -21,17 +21,14 @@
 import os
 import platform
 import sys
-
-
 from distutils.errors import CCompilerError
 from distutils.errors import DistutilsExecError
 from distutils.errors import DistutilsPlatformError
 
-
 from setuptools import Extension
-from setuptools.command.build_ext import build_ext
 from setuptools import find_packages
 from setuptools import setup
+from setuptools.command.build_ext import build_ext
 
 
 class optional_build_ext(build_ext):
diff --git a/src/zope/security/__init__.py b/src/zope/security/__init__.py
index d6f39f4..ca44b1f 100644
--- a/src/zope/security/__init__.py
+++ b/src/zope/security/__init__.py
@@ -14,10 +14,10 @@
 """Base security system
 
 """
-from zope.security.management import checkPermission
-from zope.security.checker import canWrite, canAccess
-
 # We need the injection of DecoratedSecurityCheckerDescriptor into
 # zope.location's LocationProxy as soon someone uses security proxies by
 # importing zope.security.proxy:
 import zope.security.decorator
+from zope.security.checker import canAccess
+from zope.security.checker import canWrite
+from zope.security.management import checkPermission
diff --git a/src/zope/security/_compat.py b/src/zope/security/_compat.py
index 6f7dc0a..99f0d75 100644
--- a/src/zope/security/_compat.py
+++ b/src/zope/security/_compat.py
@@ -13,11 +13,12 @@
 ##############################################################################
 """ Python 2 / 3 compatibility
 """
-import platform
 import os
+import platform
 import sys
 import types
 
+
 py_impl = getattr(platform, 'python_implementation', lambda: None)
 PYPY = py_impl() == 'PyPy'
 PURE_PYTHON = os.environ.get('PURE_PYTHON', PYPY)
diff --git a/src/zope/security/_definitions.py b/src/zope/security/_definitions.py
index 070a345..f1d0176 100644
--- a/src/zope/security/_definitions.py
+++ b/src/zope/security/_definitions.py
@@ -14,10 +14,12 @@
 """Common definitions to avoid circular imports
 """
 import threading
+
 import zope.interface
 
 from zope.security import interfaces
 
+
 thread_local = threading.local()
 
 
diff --git a/src/zope/security/adapter.py b/src/zope/security/adapter.py
index c8c44b6..0f5bc84 100644
--- a/src/zope/security/adapter.py
+++ b/src/zope/security/adapter.py
@@ -14,9 +14,11 @@
 """Support for taking security into account in adaptation
 """
 
+from zope.location import ILocation
+from zope.location import LocationProxy
+
 from zope.security.checker import ProxyFactory
 from zope.security.proxy import removeSecurityProxy
-from zope.location import ILocation, LocationProxy
 
 
 def assertLocation(adapter, parent):
diff --git a/src/zope/security/checker.py b/src/zope/security/checker.py
index fbc0b2a..ae8ab5a 100644
--- a/src/zope/security/checker.py
+++ b/src/zope/security/checker.py
@@ -58,36 +58,37 @@ API
 .. autofunction:: selectChecker
 """
 import abc
+import datetime
+import decimal
 import os
 import sys
 import types
-import datetime
-import decimal
 import weakref
 
-from zope.i18nmessageid import Message
+import zope.interface.declarations
 import zope.interface.interface
 import zope.interface.interfaces
-import zope.interface.declarations
+from zope.i18nmessageid import Message
 from zope.interface import Interface
 from zope.interface import directlyProvides
 from zope.interface import implementer
 from zope.interface.interfaces import IDeclaration
 from zope.interface.interfaces import IInterface
 
+from zope.security._compat import CLASS_TYPES
+from zope.security._compat import PURE_PYTHON
+from zope.security._compat import PYTHON2
+from zope.security._compat import implementer_if_needed
+from zope.security._definitions import thread_local
+from zope.security.interfaces import ForbiddenAttribute
 from zope.security.interfaces import IChecker
 from zope.security.interfaces import INameBasedChecker
 from zope.security.interfaces import ISecurityProxyFactory
-from zope.security.interfaces import ForbiddenAttribute
 from zope.security.interfaces import Unauthorized
-from zope.security._definitions import thread_local
-from zope.security._compat import CLASS_TYPES
-from zope.security._compat import PYTHON2
-from zope.security._compat import PURE_PYTHON
-from zope.security._compat import implementer_if_needed
 from zope.security.proxy import Proxy
 from zope.security.proxy import getChecker
 
+
 try:
     from zope.exceptions import DuplicationError
 except ImportError:  # pragma: no cover
@@ -136,6 +137,8 @@ directlyProvides(ProxyFactory, ISecurityProxyFactory)
 
 # This import represents part of the API for the proxy module
 from . import proxy  # noqa: E402 module level import not at top
+
+
 proxy.ProxyFactory = ProxyFactory
 
 
@@ -514,10 +517,12 @@ if _c_available:  # pragma: no cover
         _c_available = False
 
 if _c_available:  # pragma: no cover
-    from zope.security._zope_security_checker import _checkers, selectChecker
-    from zope.security._zope_security_checker import NoProxy, Checker
-    from zope.security._zope_security_checker import _defaultChecker
+    from zope.security._zope_security_checker import Checker
+    from zope.security._zope_security_checker import NoProxy
     from zope.security._zope_security_checker import _available_by_default
+    from zope.security._zope_security_checker import _checkers
+    from zope.security._zope_security_checker import _defaultChecker
+    from zope.security._zope_security_checker import selectChecker
     zope.interface.classImplements(Checker, INameBasedChecker)
 
 
@@ -940,6 +945,7 @@ def _fixup_odict():
     # uses view classes) and CPython 3.5+ (implemented in C). These should
     # all be iterable.
     from collections import OrderedDict
+
     # The `_fixup_dictlike` is detected as undefined because it is deleted
     # later on but this function is called beforehand:
     _fixup_dictlike(OrderedDict)  # noqa: F821 undefined name '_fixup_dictlike'
@@ -992,8 +998,8 @@ def _fixup_zope_interface():
     # checking process at all, much like BTrees, so NoProxy is necessary for
     # compatibility. On Python 3, prior to this, iteration was simply not
     # allowed.
-    from zope.interface import providedBy
     from zope.interface import alsoProvides
+    from zope.interface import providedBy
 
     class I1(Interface):
         pass
diff --git a/src/zope/security/decorator.py b/src/zope/security/decorator.py
index 0f9f2f4..18751d8 100644
--- a/src/zope/security/decorator.py
+++ b/src/zope/security/decorator.py
@@ -17,8 +17,8 @@ Decorators are proxies that are mostly transparent but that may provide
 additional features.
 """
 
-from zope.proxy import getProxiedObject
 from zope.proxy import ProxyBase
+from zope.proxy import getProxiedObject
 from zope.proxy.decorator import SpecificationDecoratorBase
 
 from zope.security.checker import CombinedChecker
@@ -75,5 +75,7 @@ class DecoratorBase(SpecificationDecoratorBase, SecurityCheckerDecoratorBase):
 # This is the only sane place we found for doing it: it kicks in as soon
 # as someone starts using security proxies.
 import zope.location.location  # noqa: E402 module level import not at top
+
+
 zope.location.location.LocationProxy.__Security_checker__ = (
     DecoratedSecurityCheckerDescriptor())
diff --git a/src/zope/security/examples/sandbox.py b/src/zope/security/examples/sandbox.py
index eb6499f..70dd5a8 100644
--- a/src/zope/security/examples/sandbox.py
+++ b/src/zope/security/examples/sandbox.py
@@ -13,10 +13,11 @@
 ##############################################################################
 """A small sandbox application.
 """
-import time
 import random
+import time
 
-from zope.interface import Interface, implementer
+from zope.interface import Interface
+from zope.interface import implementer
 
 
 class IAgent(Interface):
diff --git a/src/zope/security/examples/sandbox_security.py b/src/zope/security/examples/sandbox_security.py
index 5115ca7..d102c5f 100644
--- a/src/zope/security/examples/sandbox_security.py
+++ b/src/zope/security/examples/sandbox_security.py
@@ -27,10 +27,13 @@ secure mode. There are several steps that are taken to set up the security
   5. proxy wrap as necessary
 """
 import sandbox
-from zope.security.interfaces import IParticipation
-from zope.security import checker, management, simplepolicies
 from zope.interface import implementer
 
+from zope.security import checker
+from zope.security import management
+from zope.security import simplepolicies
+from zope.security.interfaces import IParticipation
+
 
 # Define all permissions that will be available
 NotAllowed = 'Not Allowed'
diff --git a/src/zope/security/i18n.py b/src/zope/security/i18n.py
index fc47f88..0db0317 100644
--- a/src/zope/security/i18n.py
+++ b/src/zope/security/i18n.py
@@ -17,4 +17,6 @@ __docformat__ = 'restructuredtext'
 
 # import this as _ to create i18n messages in the zope domain
 from zope.i18nmessageid import MessageFactory
+
+
 ZopeMessageFactory = MessageFactory('zope')
diff --git a/src/zope/security/interfaces.py b/src/zope/security/interfaces.py
index 890e6fc..c1cb155 100644
--- a/src/zope/security/interfaces.py
+++ b/src/zope/security/interfaces.py
@@ -51,11 +51,18 @@ means the name of the permission, or the special object
 :class:`zope.security.checker.CheckerPublic`.
 """
 
-from zope.interface import Interface, Attribute, implementer
-from zope.interface.common.interfaces import IException, IAttributeError
-from zope.schema import Text, TextLine, NativeStringLine
+from zope.interface import Attribute
+from zope.interface import Interface
+from zope.interface import implementer
+from zope.interface.common.interfaces import IAttributeError
+from zope.interface.common.interfaces import IException
+from zope.schema import NativeStringLine
+from zope.schema import Text
+from zope.schema import TextLine
+
 from zope.security.i18n import ZopeMessageFactory as _
 
+
 #: The name (id) of the registered :class:`IPermission` utility that signifies
 #: that the protected attribute is public.
 #:
diff --git a/src/zope/security/management.py b/src/zope/security/management.py
index 2daf0ce..bf79f28 100644
--- a/src/zope/security/management.py
+++ b/src/zope/security/management.py
@@ -20,13 +20,13 @@ Note that this module itself provides those interfaces.
 
 from zope.interface import moduleProvides
 
+from zope.security._definitions import system_user
+from zope.security._definitions import thread_local
 from zope.security.checker import CheckerPublic
 from zope.security.interfaces import IInteractionManagement
 from zope.security.interfaces import ISecurityManagement
 from zope.security.interfaces import NoInteraction
 from zope.security.simplepolicies import ParanoidSecurityPolicy
-from zope.security._definitions import thread_local
-from zope.security._definitions import system_user
 
 
 __all__ = [
diff --git a/src/zope/security/metaconfigure.py b/src/zope/security/metaconfigure.py
index ee437da..b09c725 100644
--- a/src/zope/security/metaconfigure.py
+++ b/src/zope/security/metaconfigure.py
@@ -17,22 +17,22 @@ __docformat__ = 'restructuredtext'
 
 from types import ModuleType
 
-from zope.component.interfaces import IFactory
 from zope.component.factory import Factory
 from zope.component.interface import provideInterface
+from zope.component.interfaces import IFactory
 from zope.component.zcml import utility
+from zope.configuration.exceptions import ConfigurationError
 from zope.interface import classImplements
 from zope.schema.interfaces import IField
-from zope.configuration.exceptions import ConfigurationError
 
 from zope.security.checker import Checker
 from zope.security.checker import CheckerPublic
 from zope.security.checker import defineChecker
 from zope.security.checker import moduleChecker
+from zope.security.interfaces import PUBLIC_PERMISSION_NAME as PublicPermission
 from zope.security.protectclass import protectLikeUnto
 from zope.security.protectclass import protectName
 from zope.security.protectclass import protectSetAttribute
-from zope.security.interfaces import PUBLIC_PERMISSION_NAME as PublicPermission
 
 
 def dottedName(klass):
diff --git a/src/zope/security/metadirectives.py b/src/zope/security/metadirectives.py
index 3e85cfd..c7e82e2 100644
--- a/src/zope/security/metadirectives.py
+++ b/src/zope/security/metadirectives.py
@@ -16,10 +16,12 @@
 __docformat__ = 'restructuredtext'
 
 import zope.configuration.fields
-from zope.configuration.fields import GlobalObject, GlobalInterface
-from zope.configuration.fields import Tokens, PythonIdentifier
 import zope.interface
 import zope.schema
+from zope.configuration.fields import GlobalInterface
+from zope.configuration.fields import GlobalObject
+from zope.configuration.fields import PythonIdentifier
+from zope.configuration.fields import Tokens
 from zope.interface import Interface
 
 import zope.security.zcml
diff --git a/src/zope/security/permission.py b/src/zope/security/permission.py
index da0dd40..8fc2837 100644
--- a/src/zope/security/permission.py
+++ b/src/zope/security/permission.py
@@ -26,8 +26,8 @@ from zope.schema.vocabulary import SimpleTerm
 from zope.schema.vocabulary import SimpleVocabulary
 
 from zope.security.checker import CheckerPublic
-from zope.security.interfaces import IPermission
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
+from zope.security.interfaces import IPermission
 
 
 @implementer(IPermission)
diff --git a/src/zope/security/proxy.py b/src/zope/security/proxy.py
index 1f4281c..52a7189 100644
--- a/src/zope/security/proxy.py
+++ b/src/zope/security/proxy.py
@@ -20,8 +20,9 @@ import functools
 import sys
 
 from zope.proxy import PyProxyBase
-from zope.security._compat import PURE_PYTHON
+
 from zope.security._compat import _BUILTINS
+from zope.security._compat import PURE_PYTHON
 
 
 def _check_name(meth, wrap_result=True):
diff --git a/src/zope/security/simplepolicies.py b/src/zope/security/simplepolicies.py
index d1617ce..feaa104 100644
--- a/src/zope/security/simplepolicies.py
+++ b/src/zope/security/simplepolicies.py
@@ -21,10 +21,10 @@ that the classes themselves are implementations of
 """
 import zope.interface
 
+from zope.security._definitions import system_user
 from zope.security.checker import CheckerPublic
 from zope.security.interfaces import IInteraction
 from zope.security.interfaces import ISecurityPolicy
-from zope.security._definitions import system_user
 
 
 @zope.interface.implementer(IInteraction)
diff --git a/src/zope/security/testing.py b/src/zope/security/testing.py
index 792813f..be551ce 100644
--- a/src/zope/security/testing.py
+++ b/src/zope/security/testing.py
@@ -19,15 +19,16 @@ This module provides some helper/stub objects for setting up interactions.
 import contextlib
 import re
 
-from zope import interface, component
+from zope.testing import renormalizing
 
-from zope.security import interfaces
-from zope.security.permission import Permission
 import zope.security.management
+from zope import component
+from zope import interface
+from zope.security import interfaces
 from zope.security._compat import PYTHON2 as PY2
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME
+from zope.security.permission import Permission
 
-from zope.testing import renormalizing
 
 _str_prefix = 'b' if PY2 else 'u'
 
diff --git a/src/zope/security/tests/test_adapter.py b/src/zope/security/tests/test_adapter.py
index 2d68b0e..20a3975 100644
--- a/src/zope/security/tests/test_adapter.py
+++ b/src/zope/security/tests/test_adapter.py
@@ -19,6 +19,7 @@ from zope.location import ILocation
 from zope.location import LocationProxy
 from zope.proxy import getProxiedObject
 
+
 # pylint:disable=attribute-defined-outside-init,protected-access
 
 
@@ -217,8 +218,8 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         self.assertEqual(after, before)  # no added attrs
 
     def test__call__w_ILocation_w_spacesuit(self):
-        from zope.security.proxy import getObject
         from zope.security.proxy import ProxyFactory
+        from zope.security.proxy import getObject
         from zope.security.proxy import removeSecurityProxy
         factory = self._makeFactory()
         factory.__parent__ = factory.__name__ = None
@@ -244,8 +245,8 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         self.assertEqual(after, before)  # no added attrs
 
     def test__call__w_ILocation_w_spacesuit_w_existing_parent(self):
-        from zope.security.proxy import getObject
         from zope.security.proxy import ProxyFactory
+        from zope.security.proxy import getObject
         from zope.security.proxy import removeSecurityProxy
         factory = self._makeFactory()
         factory.__name__ = None
diff --git a/src/zope/security/tests/test_checker.py b/src/zope/security/tests/test_checker.py
index a8b3990..a102ad6 100644
--- a/src/zope/security/tests/test_checker.py
+++ b/src/zope/security/tests/test_checker.py
@@ -16,9 +16,9 @@
 import unittest
 
 from zope.security import checker as sec_checker
-from zope.security.tests import QuietWatchingChecker
-from zope.security._compat import PYTHON3 as PY3
 from zope.security._compat import PYTHON2 as PY2
+from zope.security._compat import PYTHON3 as PY3
+from zope.security.tests import QuietWatchingChecker
 
 
 # pylint:disable=protected-access,inherit-non-class,no-method-argument,old-style-class
@@ -31,7 +31,8 @@ class Test_ProxyFactory(unittest.TestCase):
         return ProxyFactory(obj, checker)
 
     def test_w_already_proxied_no_checker(self):
-        from zope.security.proxy import Proxy, getChecker
+        from zope.security.proxy import Proxy
+        from zope.security.proxy import getChecker
         obj = object()
 
         def _check(*x):
@@ -42,7 +43,8 @@ class Test_ProxyFactory(unittest.TestCase):
         self.assertIs(getChecker(returned), _check)
 
     def test_w_already_proxied_same_checker(self):
-        from zope.security.proxy import Proxy, getChecker
+        from zope.security.proxy import Proxy
+        from zope.security.proxy import getChecker
         obj = object()
 
         def _check(*x):
@@ -80,7 +82,8 @@ class Test_ProxyFactory(unittest.TestCase):
         self.assertIs(returned, obj)
 
     def test_no_checker_w_dunder(self):
-        from zope.security.proxy import getChecker, getObject
+        from zope.security.proxy import getChecker
+        from zope.security.proxy import getObject
         _check = object()  # don't use a func, due to bound method
 
         class _WithChecker(object):
@@ -95,7 +98,8 @@ class Test_ProxyFactory(unittest.TestCase):
         from zope.security.checker import Checker
         from zope.security.checker import _checkers
         from zope.security.checker import _clear
-        from zope.security.proxy import getChecker, getObject
+        from zope.security.proxy import getChecker
+        from zope.security.proxy import getObject
 
         class _Obj(object):
             pass
@@ -221,11 +225,13 @@ class CheckerTestsBase(QuietWatchingChecker):
 
     def test_class_conforms_to_IChecker(self):
         from zope.interface.verify import verifyClass
+
         from zope.security.interfaces import IChecker
         verifyClass(IChecker, self._getTargetClass())
 
     def test_instance_conforms_to_IChecker(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IChecker
         verifyObject(IChecker, self._makeOne())
 
@@ -290,8 +296,8 @@ class CheckerTestsBase(QuietWatchingChecker):
             del thread_local.interaction
 
     def test_check_setattr_w_interaction_denies(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -338,8 +344,8 @@ class CheckerTestsBase(QuietWatchingChecker):
             del thread_local.interaction
 
     def test_check_non_public_w_interaction_denies(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -354,7 +360,8 @@ class CheckerTestsBase(QuietWatchingChecker):
             del thread_local.interaction
 
     def test_proxy_already_proxied(self):
-        from zope.security.proxy import Proxy, getChecker
+        from zope.security.proxy import Proxy
+        from zope.security.proxy import getChecker
         obj = object()
 
         def _check(*x):
@@ -372,7 +379,8 @@ class CheckerTestsBase(QuietWatchingChecker):
         self.assertIs(returned, obj)
 
     def test_proxy_no_checker_w_dunder(self):
-        from zope.security.proxy import getChecker, getObject
+        from zope.security.proxy import getChecker
+        from zope.security.proxy import getObject
         _check = object()  # don't use a func, due to bound method
 
         class _WithChecker(object):
@@ -388,7 +396,8 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security.checker import Checker
         from zope.security.checker import _checkers
         from zope.security.checker import _clear
-        from zope.security.proxy import getChecker, getObject
+        from zope.security.proxy import getChecker
+        from zope.security.proxy import getObject
 
         class _Obj(object):
             pass
@@ -408,11 +417,12 @@ class CheckerTestsBase(QuietWatchingChecker):
             _clear()
 
     def test_Decimal_operations(self):
-        from zope.security.proxy import Proxy
-        from zope.security.checker import _default_checkers
         from decimal import Decimal
         from decimal import DecimalTuple
 
+        from zope.security.checker import _default_checkers
+        from zope.security.proxy import Proxy
+
         checker = _default_checkers[Decimal]
 
         value = Decimal('1.1')
@@ -450,8 +460,8 @@ class CheckerTestsBase(QuietWatchingChecker):
         self.assertEqual(proxy.quantize(Decimal('1.10')), Decimal('1.10'))
 
     def _check_iteration_of_dict_like(self, dict_like):
-        from zope.security.proxy import Proxy
         from zope.security.checker import _default_checkers
+        from zope.security.proxy import Proxy
 
         checker = _default_checkers[dict]
 
@@ -492,12 +502,12 @@ class CheckerTestsBase(QuietWatchingChecker):
     def test_iteration_of_interface_implementedBy(self):
         # Iteration of implementedBy is allowed by default
         # See https://github.com/zopefoundation/zope.security/issues/27
-        from zope.security.proxy import Proxy
-        from zope.security.checker import Checker
-
-        from zope.interface import providedBy
-        from zope.interface import implementer
         from zope.interface import Interface
+        from zope.interface import implementer
+        from zope.interface import providedBy
+
+        from zope.security.checker import Checker
+        from zope.security.proxy import Proxy
 
         class I1(Interface):
             pass
@@ -521,13 +531,13 @@ class CheckerTestsBase(QuietWatchingChecker):
     def test_iteration_of_interface_providesBy(self):
         # Iteration of zope.interface.Provides is allowed by default
         # See https://github.com/zopefoundation/zope.security/issues/27
-        from zope.security.proxy import Proxy
-        from zope.security.checker import Checker
-
-        from zope.interface import providedBy
+        from zope.interface import Interface
         from zope.interface import alsoProvides
         from zope.interface import implementer
-        from zope.interface import Interface
+        from zope.interface import providedBy
+
+        from zope.security.checker import Checker
+        from zope.security.proxy import Proxy
 
         class I1(Interface):
             pass
@@ -558,8 +568,8 @@ class CheckerTestsBase(QuietWatchingChecker):
         # __length_hint__ method to be defined on iterators. It should
         # be allowed by default. See
         # https://github.com/zopefoundation/zope.security/issues/27
-        from zope.security.proxy import Proxy
         from zope.security.checker import _iteratorChecker
+        from zope.security.proxy import Proxy
 
         class Iter(object):
             __Security_checker__ = _iteratorChecker
@@ -607,10 +617,10 @@ class CheckerTestsBase(QuietWatchingChecker):
     def test_iteration_of_itertools_groupby(self):
         # itertools.groupby is a custom iterator type.
         # The groups it returns are also custom.
-        from zope.security.checker import ProxyFactory
-
         from itertools import groupby
 
+        from zope.security.checker import ProxyFactory
+
         group = groupby([0])
         list_group = list(group)
         self.assertEqual(1, len(list_group))
@@ -732,6 +742,7 @@ class Test_NamesChecker(unittest.TestCase):
 
     def test_empty_names_no_kw(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IChecker
         checker = self._callFUT()
         verifyObject(IChecker, checker)
@@ -780,6 +791,7 @@ class Test_InterfaceChecker(unittest.TestCase):
     def test_simple_iface_wo_kw(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import CheckerPublic
 
         class IFoo(Interface):
@@ -801,6 +813,7 @@ class Test_InterfaceChecker(unittest.TestCase):
     def test_simple_iface_w_kw(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import CheckerPublic
 
         class IFoo(Interface):
@@ -814,6 +827,7 @@ class Test_InterfaceChecker(unittest.TestCase):
     def test_derived_iface(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import CheckerPublic
 
         class IFoo(Interface):
@@ -829,6 +843,7 @@ class Test_InterfaceChecker(unittest.TestCase):
     def test_w_clash(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import DuplicationError
 
         class IFoo(Interface):
@@ -847,6 +862,7 @@ class Test_MultiChecker(unittest.TestCase):
 
     def test_empty(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IChecker
         checker = self._callFUT([])
         verifyObject(IChecker, checker)
@@ -874,6 +890,7 @@ class Test_MultiChecker(unittest.TestCase):
     def test_w_spec_as_names_and_iface(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import CheckerPublic
 
         class IFoo(Interface):
@@ -889,6 +906,7 @@ class Test_MultiChecker(unittest.TestCase):
     def test_w_spec_as_names_and_iface_clash(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.checker import CheckerPublic
         from zope.security.checker import DuplicationError
 
@@ -938,6 +956,7 @@ class _SelectCheckerBase(object):
 
     def test_w_basic_types_NoProxy(self):
         import datetime
+
         from zope.i18nmessageid import Message
         msg = Message('msg')
         for obj in [object(),
@@ -1018,9 +1037,10 @@ class _SelectCheckerBase(object):
         self.assertIs(self._callFUT(Foo()), checker)
 
     def test_itertools_checkers(self):
-        from zope.security.checker import _iteratorChecker
         import itertools
 
+        from zope.security.checker import _iteratorChecker
+
         def pred(x):
             return x
         iterable = (1, 2, 3)
@@ -1139,6 +1159,7 @@ class Test_defineChecker(unittest.TestCase):
 
     def test_w_duplicate(self):
         from zope.exceptions import DuplicationError
+
         from zope.security.checker import _checkers
 
         class Foo(object):
@@ -1158,6 +1179,7 @@ class Test_defineChecker(unittest.TestCase):
 
     def test_w_module(self):
         import zope.interface
+
         from zope.security.checker import _checkers
         checker = object()
         self._callFUT(zope.interface, checker)
@@ -1226,17 +1248,19 @@ class TestCombinedChecker(QuietWatchingChecker,
 
     def test_class_conforms_to_IChecker(self):
         from zope.interface.verify import verifyClass
+
         from zope.security.interfaces import IChecker
         verifyClass(IChecker, self._getTargetClass())
 
     def test_instance_conforms_to_IChecker(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IChecker
         verifyObject(IChecker, self._makeOne())
 
     def test_check_lhs_ok_rhs_not_called(self):
-        from zope.security.checker import CheckerPublic
         from zope.security.checker import Checker
+        from zope.security.checker import CheckerPublic
 
         class _NeverCalled(Checker):
             def check(self, object, name):  # pylint:disable=redefined-builtin
@@ -1248,8 +1272,8 @@ class TestCombinedChecker(QuietWatchingChecker,
         combined.check(object(), 'name')  # no raise
 
     def test_check_lhs_unauth_rhs_ok(self):
-        from zope.security.checker import CheckerPublic
         from zope.security._definitions import thread_local
+        from zope.security.checker import CheckerPublic
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1265,8 +1289,8 @@ class TestCombinedChecker(QuietWatchingChecker,
             del thread_local.interaction
 
     def test_check_lhs_unauth_rhs_forbidden(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1283,8 +1307,8 @@ class TestCombinedChecker(QuietWatchingChecker,
             del thread_local.interaction
 
     def test_check_lhs_unauth_rhs_unauth(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1318,8 +1342,8 @@ class TestCombinedChecker(QuietWatchingChecker,
                           combined.check, object(), 'name')
 
     def test_check_lhs_forbidden_rhs_unauth(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1336,8 +1360,8 @@ class TestCombinedChecker(QuietWatchingChecker,
             del thread_local.interaction
 
     def test_check_setattr_lhs_ok_rhs_not_called(self):
-        from zope.security.checker import CheckerPublic
         from zope.security.checker import Checker
+        from zope.security.checker import CheckerPublic
 
         class _NeverCalled(Checker):
             def check_setattr(self, object, name):
@@ -1349,8 +1373,8 @@ class TestCombinedChecker(QuietWatchingChecker,
         combined.check_setattr(object(), 'name')  # no raise
 
     def test_check_setattr_lhs_unauth_rhs_ok(self):
-        from zope.security.checker import CheckerPublic
         from zope.security._definitions import thread_local
+        from zope.security.checker import CheckerPublic
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1366,8 +1390,8 @@ class TestCombinedChecker(QuietWatchingChecker,
             del thread_local.interaction
 
     def test_check_setattr_lhs_unauth_rhs_forbidden(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1384,8 +1408,8 @@ class TestCombinedChecker(QuietWatchingChecker,
             del thread_local.interaction
 
     def test_check_setattr_lhs_unauth_rhs_unauth(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1419,8 +1443,8 @@ class TestCombinedChecker(QuietWatchingChecker,
                           combined.check_setattr, object(), 'name')
 
     def test_check_setattr_lhs_forbidden_rhs_unauth(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security._definitions import thread_local
+        from zope.security.interfaces import Unauthorized
 
         class _Interaction(object):
             def checkPermission(self, obj, perm):
@@ -1662,6 +1686,7 @@ class Test_moduleChecker(unittest.TestCase):
 
     def test_hit(self):
         from zope.interface import verify
+
         from zope.security.checker import _checkers
         checker = _checkers[verify] = object()
         self.assertIs(self._callFUT(verify), checker)
@@ -1700,6 +1725,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
     def _makeSecurityPolicy(self):
         from zope.interface import implementer
+
         from zope.security.interfaces import ISecurityPolicy
 
         @implementer(ISecurityPolicy)
@@ -1709,8 +1735,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         return SecurityPolicy
 
     def test_defineChecker_oldstyle_class(self):
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
         old_type = self._get_old_class_type()
 
         class ClassicClass:
@@ -1720,8 +1746,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         defineChecker(ClassicClass, NamesChecker())
 
     def test_defineChecker_newstyle_class(self):
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
 
         class NewStyleClass(object):
             pass
@@ -1730,13 +1756,13 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
     def test_defineChecker_module(self):
         import zope.security
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
         defineChecker(zope.security, NamesChecker())
 
     def test_defineChecker_error(self):
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
         not_a_type = object()
         self.assertRaises(TypeError,
                           defineChecker, not_a_type, NamesChecker())
@@ -1783,10 +1809,10 @@ class TestSecurityPolicy(QuietWatchingChecker,
     # - allow and disallow by permission
     def test_check_getattr(self):
         # pylint:disable=attribute-defined-outside-init
+        from zope.security.checker import CheckerPublic
+        from zope.security.checker import NamesChecker
         from zope.security.interfaces import Forbidden
         from zope.security.interfaces import Unauthorized
-        from zope.security.checker import NamesChecker
-        from zope.security.checker import CheckerPublic
 
         OldInst, NewInst = self._makeClasses()
 
@@ -1834,10 +1860,10 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
     def test_check_setattr(self):
         # pylint:disable=attribute-defined-outside-init
-        from zope.security.interfaces import Forbidden
-        from zope.security.interfaces import Unauthorized
         from zope.security.checker import Checker
         from zope.security.checker import CheckerPublic
+        from zope.security.interfaces import Forbidden
+        from zope.security.interfaces import Unauthorized
 
         OldInst, NewInst = self._makeClasses()
 
@@ -1874,11 +1900,11 @@ class TestSecurityPolicy(QuietWatchingChecker,
             self.assertRaises(Forbidden, checker.check_setattr, inst, 'f')
 
     def test_proxy(self):
-        from zope.security.proxy import getChecker
-        from zope.security.proxy import removeSecurityProxy
         from zope.security.checker import BasicTypes_examples
         from zope.security.checker import CheckerPublic
         from zope.security.checker import NamesChecker
+        from zope.security.proxy import getChecker
+        from zope.security.proxy import removeSecurityProxy
 
         OldInst, NewInst = self._makeClasses()
 
@@ -1917,9 +1943,10 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
     def testLayeredProxies(self):
         # Test that a Proxy will not be re-proxied.
-        from zope.security.proxy import Proxy, getObject
         from zope.security.checker import Checker
         from zope.security.checker import NamesChecker
+        from zope.security.proxy import Proxy
+        from zope.security.proxy import getObject
 
         class Base:
             __Security_checker__ = NamesChecker(['__Security_checker__'])
@@ -2007,8 +2034,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         self.assertEqual(checker.check(C, '__parent__'), None)
 
     def test_setattr(self):
-        from zope.security.interfaces import Forbidden
         from zope.security.checker import NamesChecker
+        from zope.security.interfaces import Forbidden
 
         OldInst, NewInst = self._makeClasses()
 
@@ -2025,12 +2052,12 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
     def test_ProxyFactory(self):
         # pylint:disable=attribute-defined-outside-init
-        from zope.security.checker import _defaultChecker
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
         from zope.security.checker import ProxyFactory
-        from zope.security.proxy import getChecker
+        from zope.security.checker import _defaultChecker
+        from zope.security.checker import defineChecker
         from zope.security.proxy import Proxy
+        from zope.security.proxy import getChecker
 
         class SomeClass(object):
             pass
@@ -2061,8 +2088,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         self.assertIs(getChecker(proxy), specific_checker)
 
     def test_define_and_undefineChecker(self):
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
         from zope.security.checker import undefineChecker
 
         class SomeClass(object):
@@ -2070,7 +2097,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         obj = SomeClass()
 
         checker = NamesChecker()
-        from zope.security.checker import _defaultChecker, selectChecker
+        from zope.security.checker import _defaultChecker
+        from zope.security.checker import selectChecker
         self.assertIs(selectChecker(obj), _defaultChecker)
         defineChecker(SomeClass, checker)
         self.assertIs(selectChecker(obj), checker)
@@ -2078,8 +2106,8 @@ class TestSecurityPolicy(QuietWatchingChecker,
         self.assertIs(selectChecker(obj), _defaultChecker)
 
     def test_ProxyFactory_using_proxy(self):
-        from zope.security.checker import ProxyFactory
         from zope.security.checker import NamesChecker
+        from zope.security.checker import ProxyFactory
 
         class SomeClass(object):
             pass
@@ -2109,11 +2137,11 @@ class TestSecurityPolicy(QuietWatchingChecker,
         # and call access to methods.
 
         # For example, consider this humble pair of class and object.
-        from zope.security.interfaces import Forbidden
         from zope.security.checker import Checker
         from zope.security.checker import canAccess
         from zope.security.checker import canWrite
         from zope.security.checker import defineChecker
+        from zope.security.interfaces import Forbidden
 
         class SomeClass(object):
             pass
@@ -2185,13 +2213,14 @@ class TestCheckerPublic(unittest.TestCase):
 
     def test_that_pickling_CheckerPublic_retains_identity(self):
         import pickle
+
         from zope.security.checker import CheckerPublic
         self.assertIs(pickle.loads(pickle.dumps(CheckerPublic)),
                       CheckerPublic)
 
     def test_that_CheckerPublic_identity_works_even_when_proxied(self):
-        from zope.security.checker import ProxyFactory
         from zope.security.checker import CheckerPublic
+        from zope.security.checker import ProxyFactory
         self.assertIs(ProxyFactory(CheckerPublic), CheckerPublic)
 
 
@@ -2224,6 +2253,7 @@ class TestMixinDecoratedChecker(unittest.TestCase):
 
     def _makeSecurityPolicy(self):
         from zope.interface import implementer
+
         from zope.security.interfaces import ISecurityPolicy
 
         @implementer(ISecurityPolicy)
@@ -2297,8 +2327,8 @@ class TestCombinedCheckerMixin(QuietWatchingChecker,
         super(TestCombinedCheckerMixin, self).tearDown()
 
     def test_checking(self):
-        from zope.security.interfaces import Unauthorized
         from zope.security.checker import CombinedChecker
+        from zope.security.interfaces import Unauthorized
         cc = CombinedChecker(self.overridingChecker, self.originalChecker)
         self.check_checking_impl(cc)
 
@@ -2319,6 +2349,7 @@ class TestCombinedCheckerMixin(QuietWatchingChecker,
 
     def test_interface(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.checker import CombinedChecker
         from zope.security.interfaces import IChecker
         dc = CombinedChecker(self.overridingChecker, self.originalChecker)
diff --git a/src/zope/security/tests/test_decorator.py b/src/zope/security/tests/test_decorator.py
index 285f7ef..756177a 100644
--- a/src/zope/security/tests/test_decorator.py
+++ b/src/zope/security/tests/test_decorator.py
@@ -14,6 +14,7 @@
 """Test zope.security.decorator
 """
 import unittest
+
 from zope.security.tests import QuietWatchingChecker
 
 
@@ -39,6 +40,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_neither_wrapper_nor_object_has_checker(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
@@ -57,6 +59,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_both_wrapper_and_object_have_checkers_not_security_proxied(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import CombinedChecker
         from zope.security.checker import NamesChecker
         from zope.security.checker import defineChecker
@@ -88,6 +91,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_only_wrapper_has_checker(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import NamesChecker
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
@@ -107,6 +111,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_only_object_has_checker(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import NamesChecker
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
@@ -126,6 +131,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_both_wrapper_and_object_have_checkers_security_proxied(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import CombinedChecker
         from zope.security.checker import NamesChecker
         from zope.security.checker import defineChecker
@@ -152,6 +158,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
 
     def test_cannot_overwrite(self):
         from zope.proxy import ProxyBase
+
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
diff --git a/src/zope/security/tests/test_location.py b/src/zope/security/tests/test_location.py
index 194fc52..a620605 100644
--- a/src/zope/security/tests/test_location.py
+++ b/src/zope/security/tests/test_location.py
@@ -16,6 +16,7 @@
 import unittest
 
 from zope.location.location import LocationProxy
+
 from zope.security.tests import QuietWatchingChecker
 
 
@@ -23,8 +24,8 @@ class LocationSecurityProxyTests(QuietWatchingChecker,
                                  unittest.TestCase):
 
     def test_locationproxy_security(self):
-        from zope.security.checker import defineChecker
         from zope.security.checker import NamesChecker
+        from zope.security.checker import defineChecker
         from zope.security.proxy import ProxyFactory
 
         class Unlocated(object):
diff --git a/src/zope/security/tests/test_management.py b/src/zope/security/tests/test_management.py
index 78dd78d..6fb62cf7 100644
--- a/src/zope/security/tests/test_management.py
+++ b/src/zope/security/tests/test_management.py
@@ -32,16 +32,17 @@ class Test(unittest.TestCase):
 
     def test_import(self):
         from zope.interface.verify import verifyObject
+
         from zope.security import management
-        from zope.security.interfaces import ISecurityManagement
         from zope.security.interfaces import IInteractionManagement
+        from zope.security.interfaces import ISecurityManagement
 
         verifyObject(ISecurityManagement, management)
         verifyObject(IInteractionManagement, management)
 
     def test_securityPolicy(self):
-        from zope.security.management import setSecurityPolicy
         from zope.security.management import getSecurityPolicy
+        from zope.security.management import setSecurityPolicy
         from zope.security.simplepolicies import PermissiveSecurityPolicy
 
         policy = PermissiveSecurityPolicy
@@ -110,9 +111,9 @@ class Test(unittest.TestCase):
         self.assertTrue(queryInteraction() is None)
 
     def test_restoreInteraction_after_neither(self):
+        from zope.security._definitions import thread_local
         from zope.security.management import queryInteraction
         from zope.security.management import restoreInteraction
-        from zope.security._definitions import thread_local
         try:
             del thread_local.interaction
         except AttributeError:
@@ -125,17 +126,17 @@ class Test(unittest.TestCase):
         self.assertTrue(queryInteraction() is None)
 
     def test_checkPermission_w_no_interaction(self):
-        from zope.security.management import checkPermission
         from zope.security.interfaces import NoInteraction
+        from zope.security.management import checkPermission
         permission = 'zope.Test'
         obj = object()
         self.assertRaises(NoInteraction, checkPermission, permission, obj)
 
     def test_checkPermission_w_interaction(self):
         from zope.security.management import checkPermission
-        from zope.security.management import setSecurityPolicy
-        from zope.security.management import queryInteraction
         from zope.security.management import newInteraction
+        from zope.security.management import queryInteraction
+        from zope.security.management import setSecurityPolicy
 
         permission = 'zope.Test'
         obj = object()
@@ -155,8 +156,8 @@ class Test(unittest.TestCase):
     def test_checkPermission_forbidden_policy(self):
         from zope.security import checkPermission
         from zope.security.checker import CheckerPublic
-        from zope.security.management import setSecurityPolicy
         from zope.security.management import newInteraction
+        from zope.security.management import setSecurityPolicy
 
         obj = object()
 
@@ -172,6 +173,7 @@ class Test(unittest.TestCase):
 
     def test_system_user(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IPrincipal
         from zope.security.interfaces import ISystemPrincipal
         from zope.security.management import system_user
diff --git a/src/zope/security/tests/test_metaconfigure.py b/src/zope/security/tests/test_metaconfigure.py
index c8631e9..a446b72 100644
--- a/src/zope/security/tests/test_metaconfigure.py
+++ b/src/zope/security/tests/test_metaconfigure.py
@@ -14,6 +14,7 @@
 """Test ZCML directives
 """
 import unittest
+
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
 
 
@@ -132,6 +133,7 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.component.interface import provideInterface
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.protectclass import protectName
 
         class IFoo(Interface):
@@ -158,6 +160,7 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.component.interface import provideInterface
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.protectclass import protectName
 
         class IFoo(Interface):
@@ -221,8 +224,9 @@ class ClassDirectiveTests(unittest.TestCase):
 
     def test_require_w_set_schema_normal_fields(self):
         from zope.component.interface import provideInterface
-        from zope.schema import Field
         from zope.interface import Interface
+        from zope.schema import Field
+
         from zope.security.protectclass import protectSetAttribute
 
         class IFoo(Interface):
@@ -263,8 +267,8 @@ class ClassDirectiveTests(unittest.TestCase):
 
     def test_require_w_set_schema_ignores_readonly_fields(self):
         from zope.component.interface import provideInterface
-        from zope.schema import Field
         from zope.interface import Interface
+        from zope.schema import Field
 
         class IFoo(Interface):
             bar = Field(u"Bar", readonly=True)
@@ -287,6 +291,7 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.component.interface import provideInterface
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.protectclass import protectName
 
         class IFoo(Interface):
@@ -315,6 +320,7 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.component.interface import provideInterface
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.protectclass import protectName
 
         class IFoo(Interface):
@@ -368,8 +374,8 @@ class ClassDirectiveTests(unittest.TestCase):
         self.assertEqual(directive(), ())
 
     def test_factory_wo_explicit_id(self):
-        from zope.component.interfaces import IFactory
         from zope.component.interface import provideInterface
+        from zope.component.interfaces import IFactory
         from zope.component.zcml import handler
         context = DummyZCMLContext()
         context.info = 'INFO'
@@ -394,8 +400,8 @@ class ClassDirectiveTests(unittest.TestCase):
         self.assertEqual(context._actions[1]['args'], ('', IFactory))
 
     def test_factory_w_explicit_id(self):
-        from zope.component.interfaces import IFactory
         from zope.component.interface import provideInterface
+        from zope.component.interfaces import IFactory
         from zope.component.zcml import handler
         context = DummyZCMLContext()
         context.info = 'INFO'
@@ -503,6 +509,7 @@ class Test_allow(unittest.TestCase):
     def test_w_interface(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.metaconfigure import protectModule
 
         class IFoo(Interface):
@@ -521,6 +528,7 @@ class Test_allow(unittest.TestCase):
     def test_w_both(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.metaconfigure import protectModule
 
         class IFoo(Interface):
@@ -602,6 +610,7 @@ class Test_requre(unittest.TestCase):
     def test_w_interface(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.metaconfigure import protectModule
 
         class IFoo(Interface):
@@ -621,6 +630,7 @@ class Test_requre(unittest.TestCase):
     def test_w_both(self):
         from zope.interface import Attribute
         from zope.interface import Interface
+
         from zope.security.metaconfigure import protectModule
 
         class IFoo(Interface):
diff --git a/src/zope/security/tests/test_permission.py b/src/zope/security/tests/test_permission.py
index 9e03496..075aed0 100644
--- a/src/zope/security/tests/test_permission.py
+++ b/src/zope/security/tests/test_permission.py
@@ -14,7 +14,9 @@
 """Test permissions
 """
 import unittest
+
 from zope.component.testing import PlacelessSetup
+
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
 
 
@@ -30,13 +32,15 @@ class PermissionTests(unittest.TestCase):
 
     def test_class_conforms_to_IPermission(self):
         from zope.interface.verify import verifyClass
+
         from zope.security.interfaces import IPermission
         verifyClass(IPermission, self._getTargetClass())
 
     def test_instance_conforms_to_IPermission(self):
         from zope.interface.verify import verifyObject
-        from zope.security.interfaces import IPermission
         from zope.schema import getValidationErrors
+
+        from zope.security.interfaces import IPermission
         verifyObject(IPermission, self._makeOne('testing'))
         self.assertEqual([],
                          getValidationErrors(IPermission,
@@ -70,6 +74,7 @@ class Test_checkPermission(PlacelessSetup, unittest.TestCase):
 
     def test_hit(self):
         from zope.component import provideUtility
+
         from zope.security.interfaces import IPermission
         permission = object()
         provideUtility(permission, IPermission, 'testing')
@@ -88,6 +93,7 @@ class Test_allPermissions(PlacelessSetup, unittest.TestCase):
     def test_w_registration(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.interfaces import IPermission
         permission = object()
         provideUtility(permission, IPermission, 'testing')
@@ -96,6 +102,7 @@ class Test_allPermissions(PlacelessSetup, unittest.TestCase):
     def test_skips_zope_Public(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.checker import CheckerPublic
         from zope.security.interfaces import IPermission
         permission = object()
@@ -119,6 +126,7 @@ class Test_PermissionsVocabulary(PlacelessSetup, unittest.TestCase):
     def test_w_registration(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.interfaces import IPermission
         permission = object()
         provideUtility(permission, IPermission, 'testing')
@@ -128,6 +136,7 @@ class Test_PermissionsVocabulary(PlacelessSetup, unittest.TestCase):
     def test_includes_zope_Public(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.checker import CheckerPublic
         from zope.security.interfaces import IPermission
         permission = object()
@@ -139,11 +148,12 @@ class Test_PermissionsVocabulary(PlacelessSetup, unittest.TestCase):
 
     def test_zcml_valid(self):
         from zope.configuration import xmlconfig
-        import zope.security
         from zope.interface.verify import verifyObject
-        from zope.security.interfaces import IPermission
         from zope.schema import getValidationErrors
 
+        import zope.security
+        from zope.security.interfaces import IPermission
+
         xmlconfig.file('configure.zcml', zope.security)
         vocabulary = self._callFUT()
         vocabulary = sorted(vocabulary, key=lambda term: term.token)
@@ -171,6 +181,7 @@ class Test_PermissionIdsVocabulary(PlacelessSetup, unittest.TestCase):
     def test_w_registration(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.interfaces import IPermission
         permission = object()
         provideUtility(permission, IPermission, 'testing')
@@ -181,6 +192,7 @@ class Test_PermissionIdsVocabulary(PlacelessSetup, unittest.TestCase):
     def test_includes_zope_Public(self):
         self.assertEqual(list(self._callFUT()), [])
         from zope.component import provideUtility
+
         from zope.security.checker import CheckerPublic
         from zope.security.interfaces import IPermission
         permission = object()
diff --git a/src/zope/security/tests/test_protectclass.py b/src/zope/security/tests/test_protectclass.py
index 16999e5..c1cdc09 100644
--- a/src/zope/security/tests/test_protectclass.py
+++ b/src/zope/security/tests/test_protectclass.py
@@ -14,6 +14,7 @@
 """Test handler for 'protectClass' directive
 """
 import unittest
+
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
 
 
@@ -101,8 +102,8 @@ class Test_protectLikeUnto(unittest.TestCase):
     def test_w_existing_like_unto_checker_wo_existing_checker(self):
         from zope.security.checker import Checker
         from zope.security.checker import CheckerPublic
-        from zope.security.checker import defineChecker
         from zope.security.checker import _checkers
+        from zope.security.checker import defineChecker
         permission = object()
         foo_checker = Checker({'bar': CheckerPublic}, {'bar': permission})
         defineChecker(Foo, foo_checker)
@@ -116,8 +117,8 @@ class Test_protectLikeUnto(unittest.TestCase):
     def test_w_existing_like_unto_checker_w_existing_checker(self):
         from zope.security.checker import Checker
         from zope.security.checker import CheckerPublic
-        from zope.security.checker import defineChecker
         from zope.security.checker import _checkers
+        from zope.security.checker import defineChecker
         permission1, permission2 = object(), object()
         foo_checker = Checker({'bar': CheckerPublic}, {'bar': permission2})
         defineChecker(Foo, foo_checker)
@@ -142,6 +143,7 @@ class Bar(Foo):
 def test_suite():
     return unittest.TestSuite((
         unittest.defaultTestLoader.loadTestsFromTestCase(Test_protectName),
-        unittest.defaultTestLoader.loadTestsFromTestCase(Test_protectSetAttribute),
+        unittest.defaultTestLoader.loadTestsFromTestCase(
+            Test_protectSetAttribute),
         unittest.defaultTestLoader.loadTestsFromTestCase(Test_protectLikeUnto),
     ))
diff --git a/src/zope/security/tests/test_proxy.py b/src/zope/security/tests/test_proxy.py
index d646f54..3570cad 100644
--- a/src/zope/security/tests/test_proxy.py
+++ b/src/zope/security/tests/test_proxy.py
@@ -15,7 +15,8 @@
 """
 import unittest
 
-from zope.security._compat import PYTHON2, PURE_PYTHON
+from zope.security._compat import PURE_PYTHON
+from zope.security._compat import PYTHON2
 
 
 def _skip_if_not_Py2(testfunc):
@@ -189,8 +190,8 @@ class AbstractProxyTestBase(object):
         self.assertEqual(str(proxy), str(target))
 
     def test___str___checker_forbids_str(self):
-        from zope.security.interfaces import ForbiddenAttribute
         from zope.security._compat import _BUILTINS
+        from zope.security.interfaces import ForbiddenAttribute
         from zope.security.proxy import _fmt_address
         target = object()
         checker = DummyChecker(ForbiddenAttribute)
@@ -222,8 +223,8 @@ class AbstractProxyTestBase(object):
         self.assertEqual(repr(proxy), repr(target))
 
     def test___repr___checker_forbids_str(self):
-        from zope.security.interfaces import ForbiddenAttribute
         from zope.security._compat import _BUILTINS
+        from zope.security.interfaces import ForbiddenAttribute
         from zope.security.proxy import _fmt_address
         target = object()
         checker = DummyChecker(ForbiddenAttribute)
@@ -1583,7 +1584,9 @@ class ProxyPyTests(AbstractProxyTestBase,
         self.assertIs(checker, sub.get_checker())
 
     def test_ctor_w_checker(self):
-        from zope.security.proxy import getObjectPy, getCheckerPy
+        from zope.security.proxy import getCheckerPy
+        from zope.security.proxy import getObjectPy
+
         # Can't access '_wrapped' / '_checker' in C version
         target = object()
         checker = object()
@@ -2161,6 +2164,7 @@ class ProxyFactoryTests(unittest.TestCase):
         # This used to work on Python 2, but fail on Python 3.
         # See https://github.com/zopefoundation/zope.interface/issues/141
         from zope.interface import Interface
+
         from zope.security.proxy import ProxyFactory
 
         class IFoo(Interface):
@@ -2253,7 +2257,9 @@ class LocationProxySecurityCheckerTests(unittest.TestCase):
         # Regression test for a problem introduced in 3.8.1 and fixed in
         # 3.8.3. For details see change log.
         import sys
+
         from zope.location.location import LocationProxy
+
         import zope.security
         try:
             from importlib import reload as _reload
diff --git a/src/zope/security/tests/test_simpleinteraction.py b/src/zope/security/tests/test_simpleinteraction.py
index 3135027..b5b5c4a 100644
--- a/src/zope/security/tests/test_simpleinteraction.py
+++ b/src/zope/security/tests/test_simpleinteraction.py
@@ -27,6 +27,7 @@ class TestInteraction(unittest.TestCase):
 
     def test(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IInteraction
         from zope.security.simplepolicies import ParanoidSecurityPolicy
         interaction = ParanoidSecurityPolicy()
@@ -61,6 +62,7 @@ class TestInteraction(unittest.TestCase):
 
     def testCreateInteraction(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IInteraction
         from zope.security.simplepolicies import ParanoidSecurityPolicy
         i1 = ParanoidSecurityPolicy()
diff --git a/src/zope/security/tests/test_simplepolicies.py b/src/zope/security/tests/test_simplepolicies.py
index fcbc8de..e55d0e3 100644
--- a/src/zope/security/tests/test_simplepolicies.py
+++ b/src/zope/security/tests/test_simplepolicies.py
@@ -24,11 +24,13 @@ class ConformsToIInteraction(object):
 
     def test_class_conforms_to_IInteraction(self):
         from zope.interface.verify import verifyClass
+
         from zope.security.interfaces import IInteraction
         verifyClass(IInteraction, self._getTargetClass())
 
     def test_instance_conforms_to_IInteraction(self):
         from zope.interface.verify import verifyObject
+
         from zope.security.interfaces import IInteraction
         verifyObject(IInteraction, self._makeOne())
 
diff --git a/src/zope/security/tests/test_zcml.py b/src/zope/security/tests/test_zcml.py
index 0cf9616..db04952 100644
--- a/src/zope/security/tests/test_zcml.py
+++ b/src/zope/security/tests/test_zcml.py
@@ -12,6 +12,7 @@
 #
 ##############################################################################
 import unittest
+
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
 
 
@@ -100,6 +101,7 @@ class Test_permission(unittest.TestCase):
     def test_wo_description(self):
         from zope.component.interface import provideInterface
         from zope.component.zcml import handler
+
         from zope.security.interfaces import IPermission
         context = DummyZCMLContext()
         context.info = 'INFO'
@@ -121,6 +123,7 @@ class Test_permission(unittest.TestCase):
     def test_w_description(self):
         from zope.component.interface import provideInterface
         from zope.component.zcml import handler
+
         from zope.security.interfaces import IPermission
         context = DummyZCMLContext()
         context.info = 'INFO'
@@ -196,5 +199,6 @@ def test_suite():
         unittest.defaultTestLoader.loadTestsFromTestCase(PermissionTests),
         unittest.defaultTestLoader.loadTestsFromTestCase(Test_securityPolicy),
         unittest.defaultTestLoader.loadTestsFromTestCase(Test_permission),
-        unittest.defaultTestLoader.loadTestsFromTestCase(Test_redefinePermission),
+        unittest.defaultTestLoader.loadTestsFromTestCase(
+            Test_redefinePermission),
     ))
diff --git a/src/zope/security/tests/test_zcml_functest.py b/src/zope/security/tests/test_zcml_functest.py
index 2486af6..3f5991a 100644
--- a/src/zope/security/tests/test_zcml_functest.py
+++ b/src/zope/security/tests/test_zcml_functest.py
@@ -13,8 +13,8 @@
 ##############################################################################
 """Directives Tests
 """
-import unittest
 import io
+import unittest
 
 
 def configfile(s):
@@ -49,6 +49,7 @@ class TestClassDirective(unittest.TestCase):
 
     def _meta(self):
         from zope.configuration.xmlconfig import XMLConfig
+
         import zope.security
         XMLConfig('meta.zcml', zope.security)()
 
@@ -64,6 +65,7 @@ class TestClassDirective(unittest.TestCase):
     def testImplements(self):
         from zope.component.interface import queryInterface
         from zope.configuration.xmlconfig import xmlconfig
+
         from zope.security.tests.exampleclass import ExampleClass
         from zope.security.tests.exampleclass import IExample
         self._meta()
@@ -84,6 +86,7 @@ class TestClassDirective(unittest.TestCase):
     def testMulImplements(self):
         from zope.component.interface import queryInterface
         from zope.configuration.xmlconfig import xmlconfig
+
         from zope.security.tests.exampleclass import ExampleClass
         from zope.security.tests.exampleclass import IExample
         from zope.security.tests.exampleclass import IExample2
@@ -156,6 +159,7 @@ class TestFactorySubdirective(unittest.TestCase):
 
     def _meta(self):
         from zope.configuration.xmlconfig import XMLConfig
+
         import zope.security
         XMLConfig('meta.zcml', zope.security)()
 
@@ -183,8 +187,8 @@ class TestFactorySubdirective(unittest.TestCase):
     def testFactoryNoId(self):
         from zope.component import getUtility
         from zope.component.interfaces import IFactory
-        from zope.interface.interfaces import ComponentLookupError
         from zope.configuration.xmlconfig import xmlconfig
+        from zope.interface.interfaces import ComponentLookupError
         self._meta()
         f = configfile("""
 <permission id="zope.Foo" title="Zope Foo Permission" />
@@ -242,13 +246,15 @@ class TestFactoryDirective(unittest.TestCase):
         tearDown()
 
     def meta(self):
-        import zope.security
         from zope.configuration.xmlconfig import XMLConfig
+
+        import zope.security
         XMLConfig('meta.zcml', zope.security)()
 
     def testFactory(self):
         from zope.component import createObject
         from zope.configuration.xmlconfig import xmlconfig
+
         from zope.security import proxy
         from zope.security.tests import exampleclass
         self.meta()
@@ -274,6 +280,7 @@ def _pfx(name):
 def defineDirectives():
     from zope.configuration.xmlconfig import XMLConfig
     from zope.configuration.xmlconfig import xmlconfig
+
     import zope.security
     XMLConfig('meta.zcml', zope.security)()
     xmlconfig(io.StringIO(u"""<configure
@@ -293,9 +300,10 @@ P2 = "zope.Paltry"
 class TestRequireDirective(unittest.TestCase):
 
     def setUp(self):
+        from zope.component.testing import setUp
         from zope.interface import implementer
+
         from zope.security.tests import module
-        from zope.component.testing import setUp
         setUp()
         defineDirectives()
 
@@ -344,6 +352,7 @@ class TestRequireDirective(unittest.TestCase):
 
     def test_wo_any_attributes(self):
         from zope.configuration.exceptions import ConfigurationError
+
         from zope.security.tests import module
         declaration = ('''<class class="%s">
                             <require
@@ -383,6 +392,7 @@ class TestRequireDirective(unittest.TestCase):
 
     def test_set_schema(self):
         from zope.component.interface import queryInterface
+
         from zope.security.checker import selectChecker
         from zope.security.tests import module
         self.assertEqual(queryInterface(_pfx("S")), None)
@@ -407,6 +417,7 @@ class TestRequireDirective(unittest.TestCase):
 
     def test_multiple_set_schema(self):
         from zope.component.interface import queryInterface
+
         from zope.security.checker import selectChecker
         from zope.security.tests import module
         self.assertEqual(queryInterface(_pfx("S")), None)
@@ -435,6 +446,7 @@ class TestRequireDirective(unittest.TestCase):
 
     def testSimpleInterface(self):
         from zope.component.interface import queryInterface
+
         from zope.security.tests import module
         self.assertEqual(queryInterface(_pfx("I")), None)
 
@@ -452,6 +464,7 @@ class TestRequireDirective(unittest.TestCase):
 
     def testMultipleInterface(self):
         from zope.component.interface import queryInterface
+
         from zope.security.tests import module
         self.assertEqual(queryInterface(_pfx("I3")), None)
         self.assertEqual(queryInterface(_pfx("I4")), None)
@@ -559,6 +572,7 @@ def apply_declaration(declaration):
 
 def make_dummy():
     from zope.interface import Interface
+
     import zope.security.zcml
     global IDummy
 
@@ -587,6 +601,7 @@ class DirectivesTest(unittest.TestCase):
 
     def testRedefinePermission(self):
         from zope.configuration import xmlconfig
+
         from zope.security import tests
         make_dummy()
         xmlconfig.file("redefineperms.zcml", tests)
diff --git a/src/zope/security/zcml.py b/src/zope/security/zcml.py
index 4e3c17c..1f48138 100644
--- a/src/zope/security/zcml.py
+++ b/src/zope/security/zcml.py
@@ -22,9 +22,9 @@ from zope.schema import Id
 from zope.schema.interfaces import IFromUnicode
 
 from zope.security._compat import implementer_if_needed
-from zope.security.permission import checkPermission
-from zope.security.management import setSecurityPolicy
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
+from zope.security.management import setSecurityPolicy
+from zope.security.permission import checkPermission
 
 
 @implementer_if_needed(IFromUnicode)
@@ -94,9 +94,10 @@ class IPermissionDirective(Interface):
 
 
 def permission(_context, id, title, description=u''):
+    from zope.component.zcml import utility
+
     from zope.security.interfaces import IPermission
     from zope.security.permission import Permission
-    from zope.component.zcml import utility
     permission = Permission(id, title, description)
     utility(_context, IPermission, permission, name=id)
 
diff --git a/tox.ini b/tox.ini
index 8931aaa..76501b1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -52,6 +52,8 @@ commands =
 basepython = python3
 skip_install = true
 commands =
+    isort --check-only --diff {toxinidir}/src {toxinidir}/setup.py
+    flake8 src setup.py
     check-manifest
     check-python-versions
 deps =