Lint the code.

21 files changed, 179 insertions, 130 deletions

diff --git a/.meta.toml b/.meta.toml
index 0ed4ba8..425a0e1 100644
--- a/.meta.toml
+++ b/.meta.toml
@@ -17,3 +17,14 @@ use-flake8 = true
 
 [coverage]
 fail-under = 99
+
+[flake8]
+additional-config = [
+    "# F401 imported but unused",
+    "# E402 module level import not at top of file",
+    "per-file-ignores =",
+    "    src/zope/traversing/adapters.py: F401",
+    "    src/zope/traversing/api.py: E402",
+    "    src/zope/traversing/browser/__init__.py: F401",
+    "    src/zope/traversing/interfaces.py: F401",
+    ]
diff --git a/setup.cfg b/setup.cfg
index 1ecf58c..8c26a7e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -5,6 +5,13 @@ universal = 1
 
 [flake8]
 doctests = 1
+# F401 imported but unused
+# E402 module level import not at top of file
+per-file-ignores =
+    src/zope/traversing/adapters.py: F401
+    src/zope/traversing/api.py: E402
+    src/zope/traversing/browser/__init__.py: F401
+    src/zope/traversing/interfaces.py: F401
 
 [check-manifest]
 ignore =
diff --git a/setup.py b/setup.py
index 9a93bb2..ead881b 100644
--- a/setup.py
+++ b/setup.py
@@ -27,6 +27,7 @@ def read(filename):
     with open(filename) as f:
         return f.read()
 
+
 long_description = (read('README.rst') +
                     '\n\n' +
                     read('CHANGES.rst'))
diff --git a/src/zope/traversing/adapters.py b/src/zope/traversing/adapters.py
index f47a5c5..3ce5aee 100644
--- a/src/zope/traversing/adapters.py
+++ b/src/zope/traversing/adapters.py
@@ -157,10 +157,10 @@ def traversePathElement(obj, name, further_path, default=_marker,
     try:
         return traversable.traverse(nm, further_path)
     except UnicodeEncodeError:
-        # If we're on Python 2, and nm was a unicode string, and the traversable
-        # tried to do an attribute lookup, the nm would have been encoded using the
-        # system encoding (usually ascii). Failure to encode means invalid attribute
-        # name.
+        # If we're on Python 2, and nm was a unicode string, and the
+        # traversable tried to do an attribute lookup, the nm would have been
+        # encoded using the system encoding (usually ascii). Failure to encode
+        # means invalid attribute name.
         if default is not _marker:
             return default
         raise LocationError(obj, name)
diff --git a/src/zope/traversing/api.py b/src/zope/traversing/api.py
index 71feb3e..0f7ec65 100644
--- a/src/zope/traversing/api.py
+++ b/src/zope/traversing/api.py
@@ -206,6 +206,7 @@ def canonicalPath(path_or_object):
     # Break path into segments. Process '.' and '..' segments.
     return _normalizePath(path)
 
+
 # import this down here to avoid circular imports
 from zope.traversing.adapters import traversePathElement
 
diff --git a/src/zope/traversing/browser/absoluteurl.py b/src/zope/traversing/browser/absoluteurl.py
index c083fad..0cdddae 100644
--- a/src/zope/traversing/browser/absoluteurl.py
+++ b/src/zope/traversing/browser/absoluteurl.py
@@ -40,9 +40,10 @@ from zope.traversing.browser.interfaces import IAbsoluteURL
 
 _ = MessageFactory('zope')
 
-_insufficientContext = _("There isn't enough context to get URL information. "
-                         "This is probably due to a bug in setting up location "
-                         "information.")
+_insufficientContext = _(
+    "There isn't enough context to get URL information. "
+    "This is probably due to a bug in setting up location "
+    "information.")
 
 _safe = '@+'  # Characters that we don't want to have quoted
 
@@ -50,6 +51,7 @@ _safe = '@+'  # Characters that we don't want to have quoted
 def absoluteURL(ob, request):
     return zope.component.getMultiAdapter((ob, request), IAbsoluteURL)()
 
+
 class _EncodedUnicode(object):
 
     def __unicode__(self):
@@ -72,7 +74,7 @@ class AbsoluteURL(_EncodedUnicode,
         # beginning of the URL, such as skins, virtual host specifications and
         # so on.
         if (context is None
-            or sameProxiedObjects(context, request.getVirtualHostRoot())):
+                or sameProxiedObjects(context, request.getVirtualHostRoot())):
             return request.getApplicationURL()
 
         # first try to get the __parent__ of the object, no matter whether
@@ -117,7 +119,7 @@ class AbsoluteURL(_EncodedUnicode,
             raise TypeError(_insufficientContext)
 
         if sameProxiedObjects(context, request.getVirtualHostRoot()) or \
-               isinstance(context, Exception):
+                isinstance(context, Exception):
             return ({'name': '', 'url': self.request.getApplicationURL()}, )
 
         base = tuple(zope.component.getMultiAdapter(
diff --git a/src/zope/traversing/browser/tests.py b/src/zope/traversing/browser/tests.py
index a128a9b..dde3eeb 100644
--- a/src/zope/traversing/browser/tests.py
+++ b/src/zope/traversing/browser/tests.py
@@ -77,8 +77,10 @@ class FooLocation(object):
 
 class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
-    assertRaisesRegex = getattr(unittest.TestCase, 'assertRaisesRegex',
-                                getattr(unittest.TestCase, 'assertRaisesRegexp'))
+    assertRaisesRegex = getattr(
+        unittest.TestCase,
+        'assertRaisesRegex',
+        getattr(unittest.TestCase, 'assertRaisesRegexp'))  # PY2
 
     def setUp(self):
         PlacelessSetup.setUp(self)
@@ -132,11 +134,11 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
+                         ({'name': '', 'url': 'http://127.0.0.1'},
                           {'name': 'a', 'url': 'http://127.0.0.1/a'},
                           {'name': 'b', 'url': 'http://127.0.0.1/a/b'},
                           {'name': 'c', 'url': 'http://127.0.0.1/a/b/c'},
-                         ))
+                          ))
 
     def testParentButNoLocation(self):
         request = TestRequest()
@@ -169,10 +171,10 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
+                         ({'name': '', 'url': 'http://127.0.0.1'},
                           {'name': 'bar', 'url': 'http://127.0.0.1/bar'},
                           {'name': 'foo', 'url': 'http://127.0.0.1/bar/foo'},
-                         ))
+                          ))
 
     def testParentTrumpsAdapter(self):
         # if we have a location adapter for a content object but
@@ -190,7 +192,7 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
                          'http://127.0.0.1/foo')
 
     def testBasicContext_unicode(self):
-        #Tests so that AbsoluteURL handle unicode names as well
+        # Tests so that AbsoluteURL handle unicode names as well
         request = TestRequest()
         root = Root()
         root.__name__ = u'\u0439'
@@ -209,17 +211,18 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
                          'http://127.0.0.1/%D0%B9/%D1%82/%D0%B5/%D1%81')
 
         breadcrumbs = view.breadcrumbs()
-        self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
-                          {'name': u'\u0439', 'url': 'http://127.0.0.1/%D0%B9'},
-                          {'name': u'\u0442',
-                           'url': 'http://127.0.0.1/%D0%B9/%D1%82'},
-                          {'name': u'\u0435',
-                           'url': 'http://127.0.0.1/%D0%B9/%D1%82/%D0%B5'},
-                          {'name': u'\u0441',
-                           'url':
-                           'http://127.0.0.1/%D0%B9/%D1%82/%D0%B5/%D1%81'},
-                         ))
+        self.assertEqual(
+            breadcrumbs, (
+                {'name': '',
+                 'url': 'http://127.0.0.1'},
+                {'name': u'\u0439',
+                 'url': 'http://127.0.0.1/%D0%B9'},
+                {'name': u'\u0442',
+                 'url': 'http://127.0.0.1/%D0%B9/%D1%82'},
+                {'name': u'\u0435',
+                 'url': 'http://127.0.0.1/%D0%B9/%D1%82/%D0%B5'},
+                {'name': u'\u0441',
+                 'url': 'http://127.0.0.1/%D0%B9/%D1%82/%D0%B5/%D1%81'}))
 
     def testRetainSkin(self):
         request = TestRequest()
@@ -235,11 +238,11 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': base + ''},
+                         ({'name': '', 'url': base + ''},
                           {'name': 'a', 'url': base + '/a'},
                           {'name': 'b', 'url': base + '/a/b'},
                           {'name': 'c', 'url': base + '/a/b/c'},
-                         ))
+                          ))
 
     def testVirtualHosting(self):
         request = TestRequest()
@@ -254,10 +257,10 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
+                         ({'name': '', 'url': 'http://127.0.0.1'},
                           {'name': 'b', 'url': 'http://127.0.0.1/b'},
                           {'name': 'c', 'url': 'http://127.0.0.1/b/c'},
-                         ))
+                          ))
 
     def testVirtualHostingWithVHElements(self):
         request = TestRequest()
@@ -272,10 +275,10 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
+                         ({'name': '', 'url': 'http://127.0.0.1'},
                           {'name': 'b', 'url': 'http://127.0.0.1/b'},
                           {'name': 'c', 'url': 'http://127.0.0.1/b/c'},
-                         ))
+                          ))
 
     def testVirtualHostingInFront(self):
         request = TestRequest()
@@ -291,11 +294,11 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
 
         breadcrumbs = view.breadcrumbs()
         self.assertEqual(breadcrumbs,
-                         ({'name':  '', 'url': 'http://127.0.0.1'},
+                         ({'name': '', 'url': 'http://127.0.0.1'},
                           {'name': 'a', 'url': 'http://127.0.0.1/a'},
                           {'name': 'b', 'url': 'http://127.0.0.1/a/b'},
                           {'name': 'c', 'url': 'http://127.0.0.1/a/b/c'},
-                         ))
+                          ))
 
     def testNoContextInformation(self):
         request = TestRequest()
@@ -310,7 +313,6 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
         self.assertEqual(str(view), 'http://127.0.0.1')
         self.assertEqual(absoluteURL(None, request), 'http://127.0.0.1')
 
-
     def test_breadcrumbs_no_parent(self):
 
         view = AbsoluteURL(self, None)
@@ -345,8 +347,8 @@ class TestAbsoluteURL(PlacelessSetup, unittest.TestCase):
         browserView(type(self), '', DummyAbsoluteURL, IAbsoluteURL)
 
         request = TestRequest()
-        self.assertIsInstance(zope.component.getMultiAdapter((self, request), IAbsoluteURL),
-                              DummyAbsoluteURL)
+        self.assertIsInstance(zope.component.getMultiAdapter(
+            (self, request), IAbsoluteURL), DummyAbsoluteURL)
         context = Context()
 
         # First the view
diff --git a/src/zope/traversing/interfaces.py b/src/zope/traversing/interfaces.py
index a16b0e3..5c61f94 100644
--- a/src/zope/traversing/interfaces.py
+++ b/src/zope/traversing/interfaces.py
@@ -107,7 +107,8 @@ class ITraversalAPI(Interface):
         :param str path: a string with path segments separated by '/'.
         :keyword request: Passed in when traversing from
             presentation code.  This allows paths like "@@foo" to work.
-        :raises zope.location.interfaces.LocationError: if *path* cannot be found
+        :raises zope.location.interfaces.LocationError: if *path* cannot be
+            found
 
         .. note:: Calling `traverse` with a path argument taken from an
             untrusted source, such as an HTTP request form variable,
@@ -202,7 +203,6 @@ class BeforeTraverseEvent(ObjectEvent):
     Default implementation of `IBeforeTraverseEvent`.
     """
 
-
     def __init__(self, ob, request):
         ObjectEvent.__init__(self, ob)
         self.request = request
diff --git a/src/zope/traversing/namespace.py b/src/zope/traversing/namespace.py
index 2ecf2a1..31f4ef4 100644
--- a/src/zope/traversing/namespace.py
+++ b/src/zope/traversing/namespace.py
@@ -88,9 +88,8 @@ class ExcessiveDepth(LocationError):
     "Too many levels of containment. We don't believe them."
 
 
-def namespaceLookup(ns, name, object, request=None): # pylint:disable=redefined-builtin
-    """
-    Lookup a value from a namespace.
+def namespaceLookup(ns, name, object, request=None):
+    """Lookup a value from a namespace.
 
     We look up a value by getting an adapter from the *object* to
     :class:`~zope.traversing.interfaces.ITraversable` named *ns*.  If
@@ -154,7 +153,7 @@ def namespaceLookup(ns, name, object, request=None): # pylint:disable=redefined-
 
         >>> from zope.testing.cleanup import cleanUp
         >>> cleanUp()
-    """
+    """  # noqa: E501 line too long
     if request is not None:
         traverser = zope.component.queryMultiAdapter((object, request),
                                                      ITraversable, ns)
@@ -307,7 +306,7 @@ class acquire(SimpleHandler):
                 try:
                     # ??? what do we do if the path gets bigger?
                     path = []
-                    after = traversable.traverse(name, path) # pylint:disable=too-many-function-args,assignment-from-no-return
+                    after = traversable.traverse(name, path)
                     if path:
                         continue
                 except LocationError:
@@ -457,7 +456,7 @@ class lang(view):
     def traverse(self, name, ignored):
         self.request.shiftNameToApplication()
         languages = IModifiableUserPreferredLanguages(self.request)
-        languages.setPreferredLanguages([name]) # pylint:disable=too-many-function-args
+        languages.setPreferredLanguages([name])
         return self.context
 
 
@@ -543,7 +542,6 @@ class adapter(SimpleHandler):
     `zope.traversing.interfaces.IPathAdapter`.
     """""
 
-
     def traverse(self, name, ignored):
         """
         To demonstrate this, we need to register some adapters:
@@ -638,8 +636,8 @@ class debug(view):
             >>> Debug.providedBy(request)
             True
 
-        Interfaces already directly provided by the request are still provided by it
-        once the debug skin is applied.
+        Interfaces already directly provided by the request are still provided
+        by it once the debug skin is applied.
 
             >>> request = TestRequest()
             >>> class IFoo(Interface):
@@ -666,9 +664,9 @@ class debug(view):
             ...     print('unknown debugging flag')
             unknown debugging flag
 
-        Of course, if Python was started with the ``-O`` flag to
-        disable debugging, none of this is allowed (we simulate this
-        with a private setting on the instance):
+        Of course, if Python was started with the ``-O`` flag to disable
+        debugging, none of this is allowed (we simulate this with a private
+        setting on the instance):
 
             >>> adapter.enable_debug = False
             >>> adapter.traverse('source', ())
@@ -687,16 +685,17 @@ class debug(view):
             elif flag == 'tal':
                 request.debug.showTAL = True
             elif flag == 'errors':
-                # Note that we don't use applySkin(), because it removes all existing
-                # skins. We may want to get tracebacks while trying to debug a
-                # different skin.
-                debug_skin = zope.component.getUtility(IBrowserSkinType, 'Debug')
+                # Note that we don't use applySkin(), because it removes all
+                # existing skins. We may want to get tracebacks while trying to
+                # debug a different skin.
+                debug_skin = zope.component.getUtility(
+                    IBrowserSkinType, 'Debug')
                 alsoProvides(request, debug_skin)
             else:
                 raise ValueError("Unknown debug flag: %s" % flag)
         return self.context
 
-    if not __debug__: # pragma: no cover
+    if not __debug__:  # pragma: no cover
         # If not in debug mode, we should get an error:
         traverse.__doc__ = """Disabled debug traversal adapter
 
diff --git a/src/zope/traversing/publicationtraverse.py b/src/zope/traversing/publicationtraverse.py
index 6c03113..301d939 100644
--- a/src/zope/traversing/publicationtraverse.py
+++ b/src/zope/traversing/publicationtraverse.py
@@ -47,6 +47,7 @@ class PublicationTraverser(object):
     - This version has a method, :meth:`traverseRelativeURL`, that
       supports "browserDefault" traversal.
     """
+
     def proxy(self, ob):
         return ProxyFactory(ob)
 
diff --git a/src/zope/traversing/testing.py b/src/zope/traversing/testing.py
index bdec349..5a54f33 100644
--- a/src/zope/traversing/testing.py
+++ b/src/zope/traversing/testing.py
@@ -39,6 +39,7 @@ class Contained(object):
     __parent__ = None
     __name__ = None
 
+
 @zope.interface.implementer(IContained)
 class ContainedProxy(object):
     __parent__ = None
@@ -55,7 +56,7 @@ class ContainedProxy(object):
         if name in ['__parent__', '__name__', '__obj__']:
             self.__dict__[name] = value
             return
-        setattr(self.__obj__, name, value) # pragma: no cover
+        setattr(self.__obj__, name, value)  # pragma: no cover
 
     def __eq__(self, value):
         return self.__obj__ == value
@@ -69,7 +70,9 @@ def contained(obj, root, name=None):
     return obj
 
 # BBB: Kept for backward-compatibility, in case some package depends on it.
-def setUp(): # pragma: no cover
+
+
+def setUp():  # pragma: no cover
     zope.component.provideAdapter(Traverser, (None,), ITraverser)
     zope.component.provideAdapter(DefaultTraversable, (None,), ITraversable)
     zope.component.provideAdapter(LocationPhysicallyLocatable,
diff --git a/src/zope/traversing/tests/test_conveniencefunctions.py b/src/zope/traversing/tests/test_conveniencefunctions.py
index a42c3f3..1f8baf7 100644
--- a/src/zope/traversing/tests/test_conveniencefunctions.py
+++ b/src/zope/traversing/tests/test_conveniencefunctions.py
@@ -34,11 +34,11 @@ from zope.traversing.testing import contained
 class C(object):
     __parent__ = None
     __name__ = None
+
     def __init__(self, name):
         self.name = name
 
 
-
 class TestFunctional(PlacelessSetup, unittest.TestCase):
 
     def setUp(self):
@@ -64,7 +64,8 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
 
         self.tr = Traverser(root)
         zope.component.provideAdapter(Traverser, (None,), ITraverser)
-        zope.component.provideAdapter(DefaultTraversable, (None,), ITraversable)
+        zope.component.provideAdapter(
+            DefaultTraversable, (None,), ITraversable)
         zope.component.provideAdapter(LocationPhysicallyLocatable, (None,),
                                       ILocationInfo)
         zope.component.provideAdapter(RootPhysicallyLocatable,
@@ -75,7 +76,7 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
         self.assertEqual(
             traverse(self.item, '/folder/item'),
             self.tr.traverse('/folder/item')
-            )
+        )
 
     def test_traverse_with_default(self):
         from zope.traversing.api import traverse
@@ -90,7 +91,7 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             TypeError,
             traverse,
             self.unwrapped_item, '/folder/item'
-            )
+        )
 
     def testTraverseName(self):
         from zope.traversing.api import traverseName
@@ -123,17 +124,17 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             LocationError,
             traverseName,
             self.folder, '../root'
-            )
+        )
         self.assertRaises(
             LocationError,
             traverseName,
             self.folder, '/root'
-            )
+        )
         self.assertRaises(
             LocationError,
             traverseName,
             self.folder, './item'
-            )
+        )
 
     def testTraverseNameUnicode(self):
         from zope.interface import implementer
@@ -152,27 +153,26 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             traverseName,
             BrokenTraversable(), '')
 
-
     def testGetName(self):
         from zope.traversing.api import getName
         self.assertEqual(
             getName(self.item),
             'item'
-            )
+        )
 
     def testGetParent(self):
         from zope.traversing.api import getParent
         self.assertEqual(
             getParent(self.item),
             self.folder
-            )
+        )
 
     def testGetParentFromRoot(self):
         from zope.traversing.api import getParent
         self.assertEqual(
             getParent(self.root),
             None
-            )
+        )
 
     def testGetParentBrokenChain(self):
         from zope.traversing.api import getParent
@@ -180,7 +180,7 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             TypeError,
             getParent,
             self.broken_chain_folder
-            )
+        )
 
     def testGetParentFromUnwrapped(self):
         from zope.traversing.api import getParent
@@ -188,14 +188,14 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             TypeError,
             getParent,
             self.unwrapped_item
-            )
+        )
 
     def testGetParents(self):
         from zope.traversing.api import getParents
         self.assertEqual(
             getParents(self.item),
             [self.folder, self.root]
-            )
+        )
 
     def testGetParentsBrokenChain(self):
         from zope.traversing.api import getParents
@@ -203,35 +203,35 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             TypeError,
             getParents,
             self.broken_chain_item
-            )
+        )
 
     def testGetPath(self):
         from zope.traversing.api import getPath
         self.assertEqual(
             getPath(self.item),
             u'/folder/item'
-            )
+        )
 
     def testGetPathOfRoot(self):
         from zope.traversing.api import getPath
         self.assertEqual(
             getPath(self.root),
             u'/',
-            )
+        )
 
     def testGetNameOfRoot(self):
         from zope.traversing.api import getName
         self.assertEqual(
             getName(self.root),
             u'',
-            )
+        )
 
     def testGetRoot(self):
         from zope.traversing.api import getRoot
         self.assertEqual(
             getRoot(self.item),
             self.root
-            )
+        )
 
     def testCanonicalPath(self):
 
@@ -250,7 +250,7 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
 
             (IndexError, '/a/../..'),
             (ValueError, '/a//v'),
-            )
+        )
 
         # sequence of N-tuples:
         #   (loc_returned_as_string, input, input, ...)
@@ -263,17 +263,17 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
              # arguments to try in addition to the above
              '/xx/yy/zz',
              '/xx/./yy/ww/../zz',
-            ),
+             ),
             (u'/xx/yy/zz',
              '/xx/yy/zz',
-            ),
+             ),
             (u'/xx',
              '/xx',
-            ),
+             ),
             (u'/',
              '/',
              self.root,
-            ),
+             ),
         )
 
         from zope.traversing.api import canonicalPath
@@ -287,7 +287,6 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
                 self.assertEqual(canonicalPath(argument), correct_answer,
                                  "failure on %s" % argument)
 
-
     def test_normalizePath(self):
 
         _bad_locations = (
@@ -295,7 +294,7 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
             (ValueError, '/foo//bar'),
             (IndexError, '/a/../..'),
             (IndexError, '/a/./../..'),
-            )
+        )
 
         # sequence of N-tuples:
         #   (loc_returned_as_string, input, input, ...)
@@ -309,25 +308,24 @@ class TestFunctional(PlacelessSetup, unittest.TestCase):
              '/xx/yy/zz',
              '/xx/./yy/ww/../zz',
              '/xx/./yy/ww/./../zz',
-            ),
+             ),
             ('xx/yy/zz',
              # arguments to try in addition to the above
              'xx/yy/zz',
              'xx/./yy/ww/../zz',
              'xx/./yy/ww/./../zz',
-            ),
+             ),
             ('/xx/yy/zz',
              '/xx/yy/zz',
-            ),
+             ),
             ('/xx',
              '/xx',
-            ),
+             ),
             ('/',
              '/',
-            ),
+             ),
         )
 
-
         from zope.traversing.api import _normalizePath
 
         for error_type, value in _bad_locations:
@@ -390,14 +388,18 @@ class TestStandalone(unittest.TestCase):
     # Unlike TestFunctional, we don't register gobs of
     # adapters, making these tests more self-contained
 
-    assertRaisesRegex = getattr(unittest.TestCase, 'assertRaisesRegex',
-                                getattr(unittest.TestCase, 'assertRaisesRegexp'))
+    assertRaisesRegex = getattr(
+        unittest.TestCase,
+        'assertRaisesRegex',
+        getattr(unittest.TestCase, 'assertRaisesRegexp'))  # PY2
 
     def test_getParent_no_location_info(self):
         from zope.traversing.api import getParent
         test = self
+
         class Context(object):
             called = False
+
             def __conform__(self, iface):
                 self.called = True
                 test.assertEqual(iface, ILocationInfo)
diff --git a/src/zope/traversing/tests/test_dependencies.py b/src/zope/traversing/tests/test_dependencies.py
index 7466181..49fa092 100644
--- a/src/zope/traversing/tests/test_dependencies.py
+++ b/src/zope/traversing/tests/test_dependencies.py
@@ -1,6 +1,5 @@
 import unittest
 
-import zope.component
 from zope.configuration.xmlconfig import XMLConfig
 from zope.publisher.browser import TestRequest
 
@@ -19,9 +18,3 @@ class ZCMLDependencies(unittest.TestCase):
         import zope.traversing.namespace
         self.assertTrue(isinstance(res, zope.traversing.namespace.lang))
         self.assertTrue(res.context is self)
-
-
-def test_suite():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(ZCMLDependencies))
-    return suite
diff --git a/src/zope/traversing/tests/test_lang.py b/src/zope/traversing/tests/test_lang.py
index 23a53f8..8590161 100644
--- a/src/zope/traversing/tests/test_lang.py
+++ b/src/zope/traversing/tests/test_lang.py
@@ -34,6 +34,7 @@ class TestRequest(test_browserlanguages.TestRequest):
     def shiftNameToApplication(self):
         self.shifted = True
 
+
 class Test(CleanUp, unittest.TestCase):
 
     def setUp(self):
diff --git a/src/zope/traversing/tests/test_namespacetrversal.py b/src/zope/traversing/tests/test_namespacetrversal.py
index bde1aeb..cadbd78 100644
--- a/src/zope/traversing/tests/test_namespacetrversal.py
+++ b/src/zope/traversing/tests/test_namespacetrversal.py
@@ -37,6 +37,7 @@ class TestSimpleHandler(unittest.TestCase):
         h = namespace.SimpleHandler(42, 43)
         self.assertEqual(h.context, 42)
 
+
 class TestFunctions(unittest.TestCase):
 
     def test_getResource_not_found(self):
@@ -76,6 +77,7 @@ class TestEtc(PlacelessSetup, unittest.TestCase):
 
     def test_traverse_site_no_manager(self):
         test = self
+
         class Context(object):
             def __getattribute__(self, name):
                 test.assertEqual(name, 'getSiteManager')
@@ -91,6 +93,7 @@ class TestEtc(PlacelessSetup, unittest.TestCase):
     def test_traverse_site_lookup_error(self):
         class Context(object):
             called = False
+
             def getSiteManager(self):
                 self.called = True
                 from zope.component import ComponentLookupError
@@ -106,7 +109,8 @@ class TestEtc(PlacelessSetup, unittest.TestCase):
 
     def test_traverse_utility(self):
         from zope.traversing.interfaces import IEtcNamespace
-        component.provideUtility(self, provides=IEtcNamespace, name='my etc name')
+        component.provideUtility(
+            self, provides=IEtcNamespace, name='my etc name')
 
         result = namespace.etc(None, None).traverse('my etc name', ())
         self.assertIs(result, self)
@@ -124,14 +128,17 @@ class TestView(unittest.TestCase):
 
 class TestVh(unittest.TestCase):
 
-    assertRaisesRegex = getattr(unittest.TestCase, 'assertRaisesRegex',
-                                getattr(unittest.TestCase, 'assertRaisesRegexp'))
+    assertRaisesRegex = getattr(
+        unittest.TestCase,
+        'assertRaisesRegex',
+        getattr(unittest.TestCase, 'assertRaisesRegexp'))  # PY2
 
     def test_invalid_vh(self):
         with self.assertRaisesRegex(ValueError,
                                     'Vhost directive should have the form'):
             namespace.vh(None, None).traverse(u'invalid name', ())
 
+
 def test_suite():
     checker = RENormalizing([
         # Python 3 includes module name in exceptions
diff --git a/src/zope/traversing/tests/test_presentation.py b/src/zope/traversing/tests/test_presentation.py
index 10a9039..17b9df6 100644
--- a/src/zope/traversing/tests/test_presentation.py
+++ b/src/zope/traversing/tests/test_presentation.py
@@ -29,15 +29,18 @@ from zope.traversing.testing import browserView
 class IContent(Interface):
     pass
 
+
 @implementer(IContent)
 class Content(object):
     pass
 
+
 class Resource(object):
 
     def __init__(self, request):
         pass
 
+
 class View(object):
 
     def __init__(self, content, request):
diff --git a/src/zope/traversing/tests/test_publicationtraverse.py b/src/zope/traversing/tests/test_publicationtraverse.py
index 086177e..8218314 100644
--- a/src/zope/traversing/tests/test_publicationtraverse.py
+++ b/src/zope/traversing/tests/test_publicationtraverse.py
@@ -135,7 +135,6 @@ class TestPublicationTraverser(CleanUp, unittest.TestCase):
         self.assertRaises(
             NotFound, t.traversePath, request, ob, '/++skin++missingskin')
 
-
     def test_traversePath_trailing_slash(self):
         class Traverser(PublicationTraverser):
             def __init__(self):
@@ -144,7 +143,6 @@ class TestPublicationTraverser(CleanUp, unittest.TestCase):
             def traverseName(self, request, ob, name):
                 self.names.append(name)
 
-
         t = Traverser()
         t.traversePath(None, None, 'abc/def/')
         self.assertEqual(t.names, ['abc', 'def'])
@@ -158,7 +156,6 @@ class TestPublicationTraverser(CleanUp, unittest.TestCase):
         # complained yet.
         self.assertEqual(t.names, ['abc', 'def', '', ''])
 
-
     def test_traversePath_double_dots_cannot_remove(self):
         class Traverser(PublicationTraverser):
             def __init__(self):
@@ -167,20 +164,20 @@ class TestPublicationTraverser(CleanUp, unittest.TestCase):
             def traverseName(self, request, ob, name):
                 self.names.append(name)
 
-
         t = Traverser()
         t.traversePath(None, None, '..')
         self.assertEqual(t.names, ['..'])
 
     def test_traverseRelativeURL_to_no_browser_publisher(self):
         test = self
+
         class Traverser(PublicationTraverser):
             def traversePath(self, request, ob, path):
                 return ob
 
-
         class Context(object):
             called = False
+
             def __conform__(self, iface):
                 self.called = True
                 test.assertEqual(iface, IBrowserPublisher)
@@ -193,6 +190,7 @@ class TestPublicationTraverser(CleanUp, unittest.TestCase):
 
         self.assertTrue(context.called)
 
+
 class TestBeforeTraverseEvent(unittest.TestCase):
 
     def test_interfaces(self):
@@ -208,17 +206,21 @@ class TestBeforeTraverseEvent(unittest.TestCase):
         self.assertIs(target, ob.object)
         verifyObject(IBeforeTraverseEvent, ob)
 
+
 class IContent(Interface):
     pass
 
+
 @implementer(IContent)
 class Content(object):
     pass
 
+
 class View(object):
     def __init__(self, name):
         self.name = name
 
+
 @implementer(ITraversable)
 class DummyViewTraverser(object):
 
@@ -228,6 +230,7 @@ class DummyViewTraverser(object):
     def traverse(self, name, furtherPath):
         return View(name)
 
+
 @implementer(IPublishTraverse)
 class DummyPublishTraverse(object):
 
@@ -237,6 +240,7 @@ class DummyPublishTraverse(object):
     def publishTraverse(self, request, name):
         return View(name)
 
+
 @implementer(IBrowserPublisher)
 class DummyBrowserPublisher(object):
 
diff --git a/src/zope/traversing/tests/test_skin.py b/src/zope/traversing/tests/test_skin.py
index bd2c4d1..8460428 100644
--- a/src/zope/traversing/tests/test_skin.py
+++ b/src/zope/traversing/tests/test_skin.py
@@ -26,8 +26,11 @@ class FauxRequest(object):
     def shiftNameToApplication(self):
         self.shifted = 1
 
+
 class IFoo(Interface):
     pass
+
+
 directlyProvides(IFoo, IBrowserSkinType)
 
 
diff --git a/src/zope/traversing/tests/test_traverser.py b/src/zope/traversing/tests/test_traverser.py
index 492cccd..69ff88b 100644
--- a/src/zope/traversing/tests/test_traverser.py
+++ b/src/zope/traversing/tests/test_traverser.py
@@ -48,10 +48,12 @@ class ParticipationStub(object):
         self.principal = principal
         self.interaction = None
 
+
 class C(Contained):
     def __init__(self, name):
         self.name = name
 
+
 class TraverserTests(PlacelessSetup, unittest.TestCase):
 
     def setUp(self):
@@ -72,6 +74,7 @@ class TraverserTests(PlacelessSetup, unittest.TestCase):
     def test_traverse_empty_path_is_context(self):
         self.assertIs(self.item, self.tr.traverse(''))
 
+
 class UnrestrictedNoTraverseTests(unittest.TestCase):
     def setUp(self):
         self.root = root = C('root')
@@ -88,11 +91,13 @@ class UnrestrictedNoTraverseTests(unittest.TestCase):
         self.assertRaises(LocationError, self.tr.traverse,
                           'folder')
 
+
 class UnrestrictedTraverseTests(PlacelessSetup, unittest.TestCase):
     def setUp(self):
         PlacelessSetup.setUp(self)
 
-        zope.component.provideAdapter(DefaultTraversable, (None,), ITraversable)
+        zope.component.provideAdapter(
+            DefaultTraversable, (None,), ITraversable)
         zope.component.provideAdapter(LocationPhysicallyLocatable, (None,),
                                       ILocationInfo)
         zope.component.provideAdapter(RootPhysicallyLocatable,
@@ -158,7 +163,7 @@ class UnrestrictedTraverseTests(PlacelessSetup, unittest.TestCase):
             'foo': 'bar',
             'anotherdict': {'bar': 'foo'},
             'items': '123',
-            }
+        }
         tr = Traverser(adict)
         self.assertEqual(tr.traverse('items'), adict.items)
         self.assertEqual(tr.traverse('anotherdict/bar'), 'foo')
@@ -189,7 +194,8 @@ class RestrictedTraverseTests(PlacelessSetup, unittest.TestCase):
     def setUp(self):
         PlacelessSetup.setUp(self)
 
-        zope.component.provideAdapter(DefaultTraversable, (None,), ITraversable)
+        zope.component.provideAdapter(
+            DefaultTraversable, (None,), ITraversable)
         zope.component.provideAdapter(LocationPhysicallyLocatable, (None,),
                                       ILocationInfo)
         zope.component.provideAdapter(RootPhysicallyLocatable,
@@ -295,9 +301,11 @@ class TestFunctions(unittest.TestCase):
 
     def test_traversePathElement_UnicodeEncodeError_with_default(self):
         test = self
+
         class Traversable(object):
             called = False
             fail = test.fail
+
             def traverse(self, nm, further_path):
                 self.called = True
                 u'\xff'.encode("ascii")
@@ -310,10 +318,10 @@ class TestFunctions(unittest.TestCase):
                                                    traversable=t))
         self.assertTrue(t.called)
 
-
     def test_traversePathElement_LocationError_with_default(self):
         class Traversable(object):
             called = False
+
             def traverse(self, nm, further_path):
                 self.called = True
                 raise LocationError()
diff --git a/src/zope/traversing/tests/test_vh.py b/src/zope/traversing/tests/test_vh.py
index 70d88ec..d70c408 100644
--- a/src/zope/traversing/tests/test_vh.py
+++ b/src/zope/traversing/tests/test_vh.py
@@ -40,6 +40,7 @@ class TestRequest(object):
         del self._traversed_names[:]
         self._app_names = names or []
 
+
 class TestVHNamespace(unittest.TestCase):
 
     def test_vh(self):
@@ -66,32 +67,22 @@ class TestVHNamespace(unittest.TestCase):
         handler = vh(ob, request)
         self.assertRaises(ValueError, handler.traverse, 'http:host:80', ())
 
-
     def test_vh_host(self):
         from zope.traversing.namespace import vh
 
         request = TestRequest(['folder1'], ['folder1_1', '++'])
         ob = object()
-        result = vh(ob, request).traverse('http:www.fubarco.com:80', ())
+        vh(ob, request).traverse('http:www.fubarco.com:80', ())
 
         self.assertEqual(request._app_server, 'http://www.fubarco.com:80')
 
-
     def test_unicode_vh_host(self):
         from zope.traversing.namespace import vh
 
         request = TestRequest(['folder1'], ['folder1_1', '++'])
         ob = object()
 
-        result = vh(ob, request).traverse(u'http:www.fubarco.com:80', ())
-        self.assertTrue(isinstance(request._app_server, str), repr(request._app_server))
-
-
-def test_suite():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(TestVHNamespace))
-    return suite
-
-
-if __name__ == '__main__':
-    unittest.main()
+        vh(ob, request).traverse(u'http:www.fubarco.com:80', ())
+        self.assertTrue(
+            isinstance(request._app_server, str),
+            repr(request._app_server))
diff --git a/src/zope/traversing/tests/test_vhosting.py b/src/zope/traversing/tests/test_vhosting.py
index 137a997..df35500 100644
--- a/src/zope/traversing/tests/test_vhosting.py
+++ b/src/zope/traversing/tests/test_vhosting.py
@@ -48,9 +48,11 @@ class MyObj(Contained):
     def __getitem__(self, key):
         return traverse(self, '/foo/bar/' + key)
 
+
 class IFolder(zope.interface.Interface):
     pass
 
+
 @zope.interface.implementer(IFolder, IBrowserPublisher)
 class Folder(Contained, dict):
     def __init__(self):
@@ -64,7 +66,7 @@ class Folder(Contained, dict):
     def publishTraverse(self, request, name):
         subob = self.get(name, None)
         if subob is None:
-            raise NotFound(self.context, name, request) # pragma: no cover
+            raise NotFound(self.context, name, request)  # pragma: no cover
         return subob
 
 
@@ -87,21 +89,27 @@ class ZopeTraverser(object):
             object = traversePathElement(object, name, path_items,
                                          request=request)
         return object
+
+
 zopeTraverser = ZopeTraverser()
 
+
 class PathExpr(expressions.PathExpr):
 
     def __init__(self, name, expr, engine):
         super(PathExpr, self).__init__(name, expr, engine, zopeTraverser)
 
+
 def Engine():
     e = ExpressionEngine()
     for pt in PathExpr._default_type_names:
         e.registerType(pt, PathExpr)
     return e
 
+
 Engine = Engine()
 
+
 class MyTalesPage(object):
 
     def __init__(self, source):
@@ -131,6 +139,7 @@ class MyPageEval(BrowserView):
 
     index = __call__
 
+
 class MyFolderPage(BrowserView):
 
     def __call__(self, **kw):
@@ -242,7 +251,7 @@ class TestVirtualHosting(unittest.TestCase):
         """addFolders('/a/b/c/d') would traverse and/or create three nested
         folders (a, b, c) and return a tuple (c, 'd') where c is a Folder
         instance at /a/b/c."""
-        folder = self.app  #self.connection.root()['Application']
+        folder = self.app  # self.connection.root()['Application']
         if path[0] == '/':
             path = path[1:]
         path = path.split('/')
@@ -331,7 +340,8 @@ class DummyPublication(object):
         """Post-callObject hook (if it was successful).
         """
 
-    def handleException(self, ob, request, exc_info, retry_allowed=1): # pragma: no cover
+    def handleException(
+            self, ob, request, exc_info, retry_allowed=1):  # pragma: no cover
         """Handle an exception
 
         Either: