diff --git a/setup.py b/setup.py
index 871361f..4469f74 100644
--- a/setup.py
+++ b/setup.py
@@ -103,7 +103,7 @@ def header_dirs_for_dep(distname, headername):  # 3 and 4
     ]
 
 
-class IncludeDirs(object):
+class IncludeDirs:
     dirs = None
 
     def __getattribute__(self, name):
@@ -118,19 +118,14 @@ def __iter__(self):
         return iter(self.dirs)
 
 
-if str is bytes and hasattr(sys, 'pypy_version_info'):
-    # zope.proxy, as of 4.3.5, cannot compile on PyPy2 7.3.0
-    # because it uses cl_dict in a PyClassObject, which does not exist.
-    ext_modules = []
-else:
-    ext_modules = [
-        Extension(
-            "zope.container._zope_container_contained",
-            [os.path.join("src", "zope", "container",
-                          "_zope_container_contained.c")],
-            include_dirs=IncludeDirs(),
-        ),
-    ]
+ext_modules = [
+    Extension(
+        "zope.container._zope_container_contained",
+        [os.path.join("src", "zope", "container",
+                      "_zope_container_contained.c")],
+        include_dirs=IncludeDirs(),
+    ),
+]
 
 setup_requires = [
     'persistent >= 4.1.0',
@@ -140,7 +135,6 @@ def __iter__(self):
 
 install_requires = setup_requires + [
     'BTrees',
-    'six',
     'zope.cachedescriptors',
     'zope.component',
     'zope.deferredimport',
@@ -199,11 +193,7 @@ def __iter__(self):
           'Intended Audience :: Developers',
           'License :: OSI Approved :: Zope Public License',
           'Programming Language :: Python',
-          'Programming Language :: Python :: 2',
-          'Programming Language :: Python :: 2.7',
           'Programming Language :: Python :: 3',
-          'Programming Language :: Python :: 3.5',
-          'Programming Language :: Python :: 3.6',
           'Programming Language :: Python :: 3.7',
           'Programming Language :: Python :: 3.8',
           'Programming Language :: Python :: 3.9',
@@ -234,12 +224,5 @@ def __iter__(self):
       tests_require=extras['test'],
       include_package_data=True,
       zip_safe=False,
-      python_requires=', '.join([
-          '>=2.7',
-          '!=3.0.*',
-          '!=3.1.*',
-          '!=3.2.*',
-          '!=3.3.*',
-          '!=3.4.*',
-      ]),
+      python_requires='>=3.7',
       )
diff --git a/src/zope/container/_compat.py b/src/zope/container/_compat.py
deleted file mode 100644
index 9e9c417..0000000
--- a/src/zope/container/_compat.py
+++ /dev/null
@@ -1,6 +0,0 @@
-try:
-    # PY2
-    text_type = unicode
-except NameError:
-    # PY3
-    text_type = str
diff --git a/src/zope/container/_proxy.py b/src/zope/container/_proxy.py
index 62b7f75..aa7c41e 100644
--- a/src/zope/container/_proxy.py
+++ b/src/zope/container/_proxy.py
@@ -36,13 +36,13 @@ class ContainedProxyBase(AbstractPyProxyBase, Persistent):
     __slots__ = ('_wrapped', '__parent__', '__name__', '__weakref__')
 
     def __new__(cls, obj):
-        inst = super(ContainedProxyBase, cls).__new__(cls, obj)
+        inst = super().__new__(cls, obj)
         inst.__parent__ = None
         inst.__name__ = None
         return inst
 
     def __init__(self, obj):
-        super(ContainedProxyBase, self).__init__(obj)
+        super().__init__(obj)
         self.__parent__ = None
         self.__name__ = None
 
@@ -94,7 +94,7 @@ def __getattribute__(self, name):
         ):
             return object.__getattribute__(self, name)
 
-        return super(ContainedProxyBase, self).__getattribute__(name)
+        return super().__getattribute__(name)
 
     def __setattr__(self, name, value):
         if _special_name(name):
@@ -103,7 +103,7 @@ def __setattr__(self, name, value):
             # themselves
             return Persistent.__setattr__(self, name, value)
 
-        return super(ContainedProxyBase, self).__setattr__(name, value)
+        return super().__setattr__(name, value)
 
 
 @use_c_impl
diff --git a/src/zope/container/_util.py b/src/zope/container/_util.py
index 4fe98f4..775c0dd 100644
--- a/src/zope/container/_util.py
+++ b/src/zope/container/_util.py
@@ -157,19 +157,9 @@ def find_impl():
             if not isinstance(v, types.FunctionType):
                 continue
 
-            # Somewhat surprisingly, on Python 2, while
-            # ``Class.function`` results in a
-            # ``types.UnboundMethodType`` (``instancemethed``) object,
-            # ``Class.__dict__["function"]`` returns a
-            # ``types.FunctionType``, just like ``Class.function``
-            # (and the dictionary access, of course) does on Python 3.
-            # The upshot is, we don't need different version-dependent
-            # code. Hooray!
             if new_globals is None:
                 new_globals = v.__globals__.copy()
                 new_globals[py_impl.__name__] = py_impl
-            # On Python 2, all arguments are optional, but an Python 3, all
-            # are required.
             v = types.FunctionType(
                 v.__code__,
                 new_globals,
diff --git a/src/zope/container/_zope_container_contained.c b/src/zope/container/_zope_container_contained.c
index d21f741..7794c60 100644
--- a/src/zope/container/_zope_container_contained.c
+++ b/src/zope/container/_zope_container_contained.c
@@ -78,13 +78,8 @@ typedef struct {
 /* Incude the proxy C source */
 #include "_zope_proxy_proxy.c"
 
-#ifdef PY3K
-  #define MAKE_PYSTRING(s) PyUnicode_FromString(s)
-  #define MAKE_STRING(name) PyBytes_AS_STRING(PyUnicode_AsUTF8String(name))
-#else
-  #define MAKE_PYSTRING(s) PyString_FromString(s)
-  #define MAKE_STRING(name) PyString_AS_STRING(name)
-#endif
+#define MAKE_PYSTRING(s) PyUnicode_FromString(s)
+#define MAKE_STRING(name) PyBytes_AS_STRING(PyUnicode_AsUTF8String(name))
 
 #define SPECIAL(NAME) (                        \
     *(NAME) == '_' &&                          \
@@ -316,13 +311,8 @@ MOD_INIT(_zope_container_contained)
     empty_tuple = PyTuple_New(0);
 
   /* Initialize the PyPersist_C_API and the type objects. */
-#ifdef PY3K
-    cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCapsule_Import(
-                "persistent.cPersistence.CAPI", 0);
-#else
-    cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCObject_Import(
-                "persistent.cPersistence", "CAPI");
-#endif
+  cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCapsule_Import(
+              "persistent.cPersistence.CAPI", 0);
 
   if (cPersistenceCAPI == NULL)
     return MOD_ERROR_VAL;
diff --git a/src/zope/container/constraints.py b/src/zope/container/constraints.py
index 2020df2..1c07731 100644
--- a/src/zope/container/constraints.py
+++ b/src/zope/container/constraints.py
@@ -47,7 +47,7 @@
    >>> checkObject(c1, "Zbob", None)
    Traceback (most recent call last):
    ...
-   Invalid: Names can not start with Z
+   zope.interface.exceptions.Invalid: Names can not start with Z
 
    We can also express constaints on the containers an object can be
    added to. We do this by setting a field constraint on an object's
@@ -76,7 +76,7 @@
    >>> checkObject(c1, "bob", O())
    Traceback (most recent call last):
    ...
-   ConstraintNotSatisfied: (C1, '__parent__')
+   zope.schema._bootstrapinterfaces.ConstraintNotSatisfied: (C1, '__parent__')
 
    Note that the validation error isn't very informative. For that
    reason, it's better for constraints to raise Invalid errors when they
@@ -98,7 +98,7 @@
    >>> checkObject(c1, "bob", O())
    Traceback (most recent call last):
    ...
-   Invalid: What, no x?
+   zope.interface.exceptions.Invalid: What, no x?
 
    >>> c1.x = 1
    >>> checkObject(c1, "bob", O())
@@ -246,7 +246,7 @@ def factory(container, name, factory):
         """
 
 
-class _TypesBased(object):
+class _TypesBased:
 
     @readproperty
     def types(self):
diff --git a/src/zope/container/constraints.rst b/src/zope/container/constraints.rst
index 07beb99..4cbd83e 100644
--- a/src/zope/container/constraints.rst
+++ b/src/zope/container/constraints.rst
@@ -59,7 +59,7 @@ If we try to use other containers or folders, we'll get errors:
     >>> checkObject(Container(), 'x', Buddy())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidContainerType: ...
+    zope.container.interfaces.InvalidContainerType: ...
 
     >>> checkFactory(Container(), 'x', Factory(Buddy))
     False
@@ -67,7 +67,7 @@ If we try to use other containers or folders, we'll get errors:
     >>> checkObject(BuddyFolder(), 'x', Contained())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidItemType: ...
+    zope.container.interfaces.InvalidItemType: ...
 
     >>> checkFactory(BuddyFolder(), 'x', Factory(Contained))
     False
@@ -90,7 +90,7 @@ could have defined these in the opposite order:
     >>> checkObject(Contacts(), 'x', Buddy())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidItemType: ...
+    zope.container.interfaces.InvalidItemType: ...
 
     >>> checkFactory(Contacts(), 'x', Factory(Buddy))
     False
diff --git a/src/zope/container/contained.py b/src/zope/container/contained.py
index 8ab95cd..f1aa61a 100644
--- a/src/zope/container/contained.py
+++ b/src/zope/container/contained.py
@@ -14,7 +14,6 @@
 """Classes to support implementing `IContained`
 """
 # pylint:disable=too-many-lines
-from six import text_type
 
 import zope.component
 from zope.event import notify
@@ -50,7 +49,7 @@ class IBroken(Interface):  # pylint:disable=inherit-non-class
 
 
 @zope.interface.implementer(IContained)
-class Contained(object):
+class Contained:
     """
     Simple mix-in that defines ``__parent__`` and ``__name__``
     attributes and implements `IContained`.
@@ -157,7 +156,7 @@ def dispatchToSublocations(object, event):  # pylint:disable=redefined-builtin
             zope.component.handle(sub, event)
 
 
-class ContainerSublocations(object):
+class ContainerSublocations:
     """Get the sublocations for a container
 
        Obviously, this is the container values:
@@ -200,7 +199,7 @@ def containedEvent(object, container, name=None):
 
         >>> container = {}
         >>> item = Contained()
-        >>> x, event = containedEvent(item, container, u'foo')
+        >>> x, event = containedEvent(item, container, 'foo')
         >>> x is item
         True
         >>> item.__parent__ is container
@@ -223,7 +222,7 @@ def containedEvent(object, container, name=None):
 
     Now if we call contained again:
 
-        >>> x2, event = containedEvent(item, container, u'foo')
+        >>> x2, event = containedEvent(item, container, 'foo')
         >>> x2 is item
         True
         >>> item.__parent__ is container
@@ -238,7 +237,7 @@ def containedEvent(object, container, name=None):
     If the object already had a parent but the parent or name was
     different, we get a moved event:
 
-        >>> x, event = containedEvent(item, container, u'foo2')
+        >>> x, event = containedEvent(item, container, 'foo2')
         >>> event.__class__.__name__
         'ObjectMovedEvent'
         >>> event.object is item
@@ -353,7 +352,7 @@ def checkAndConvertName(name):
             name = name.decode('ascii')
         except UnicodeError:
             raise TypeError("name not unicode or ascii string")
-    elif not isinstance(name, text_type):
+    elif not isinstance(name, str):
         raise TypeError("name not unicode or ascii string")
 
     if not name:
@@ -391,8 +390,8 @@ def setitem(container, setitemf, name, object):
     >>> item = Item()
 
     >>> container = {}
-    >>> setitem(container, container.__setitem__, u'c', item)
-    >>> container[u'c'] is item
+    >>> setitem(container, container.__setitem__, 'c', item)
+    >>> container['c'] is item
     True
     >>> item.__parent__ is container
     True
@@ -438,7 +437,7 @@ def setitem(container, setitemf, name, object):
 
     >>> item = Item()
     >>> item.__parent__, item.__name__ = container, 'c2'
-    >>> setitem(container, container.__setitem__, u'c2', item)
+    >>> setitem(container, container.__setitem__, 'c2', item)
     >>> len(container)
     2
     >>> len(getEvents(IObjectAddedEvent))
@@ -452,7 +451,7 @@ def setitem(container, setitemf, name, object):
     If the item had a parent or name (as in a move or rename),
     we generate a move event, rather than an add event:
 
-    >>> setitem(container, container.__setitem__, u'c3', item)
+    >>> setitem(container, container.__setitem__, 'c3', item)
     >>> len(container)
     3
     >>> len(getEvents(IObjectAddedEvent))
@@ -474,14 +473,14 @@ def setitem(container, setitemf, name, object):
     If we try to replace an item without deleting it first, we'll get
     an error:
 
-    >>> setitem(container, container.__setitem__, u'c', [])
+    >>> setitem(container, container.__setitem__, 'c', [])
     Traceback (most recent call last):
     ...
-    KeyError: u'c'
+    KeyError: 'c'
 
 
-    >>> del container[u'c']
-    >>> setitem(container, container.__setitem__, u'c', [])
+    >>> del container['c']
+    >>> setitem(container, container.__setitem__, 'c', [])
     >>> len(getEvents(IObjectAddedEvent))
     2
     >>> len(getEvents(IObjectModifiedEvent))
@@ -496,13 +495,13 @@ def setitem(container, setitemf, name, object):
     >>> item = Location()
     >>> IContained.providedBy(item)
     0
-    >>> setitem(container, container.__setitem__, u'l', item)
-    >>> container[u'l'] is item
+    >>> setitem(container, container.__setitem__, 'l', item)
+    >>> container['l'] is item
     1
     >>> item.__parent__ is container
     1
     >>> item.__name__
-    u'l'
+    'l'
     >>> IContained.providedBy(item)
     1
 
@@ -517,16 +516,16 @@ def setitem(container, setitemf, name, object):
     `ContainedProxy` around it:
 
     >>> item = []
-    >>> setitem(container, container.__setitem__, u'i', item)
-    >>> container[u'i']
+    >>> setitem(container, container.__setitem__, 'i', item)
+    >>> container['i']
     []
-    >>> container[u'i'] is item
+    >>> container['i'] is item
     0
-    >>> item = container[u'i']
+    >>> item = container['i']
     >>> item.__parent__ is container
     1
     >>> item.__name__
-    u'i'
+    'i'
     >>> IContained.providedBy(item)
     1
 
@@ -559,7 +558,7 @@ def setitem(container, setitemf, name, object):
     ...
     ValueError: empty names are not allowed
 
-    >>> setitem(container, container.__setitem__, u'', item)
+    >>> setitem(container, container.__setitem__, '', item)
     Traceback (most recent call last):
     ...
     ValueError: empty names are not allowed
@@ -601,16 +600,16 @@ def uncontained(object, container, name=None):
     ...     pass
 
     >>> item = Item()
-    >>> container = {u'foo': item}
-    >>> x, event = containedEvent(item, container, u'foo')
+    >>> container = {'foo': item}
+    >>> x, event = containedEvent(item, container, 'foo')
     >>> item.__parent__ is container
     1
     >>> item.__name__
-    u'foo'
+    'foo'
 
     Now we'll remove the item. It's parent and name are cleared:
 
-    >>> uncontained(item, container, u'foo')
+    >>> uncontained(item, container, 'foo')
     >>> item.__parent__
     >>> item.__name__
 
@@ -624,7 +623,7 @@ def uncontained(object, container, name=None):
     >>> event.oldParent is container
     1
     >>> event.oldName
-    u'foo'
+    'foo'
     >>> event.newParent
     >>> event.newName
 
@@ -637,7 +636,7 @@ def uncontained(object, container, name=None):
 
     Now if we call uncontained again:
 
-    >>> uncontained(item, container, u'foo')
+    >>> uncontained(item, container, 'foo')
 
     We won't get any new events, because __parent__ and __name__ are None:
 
@@ -651,14 +650,14 @@ def uncontained(object, container, name=None):
     event.
 
     >>> item.__parent__, item.__name__ = container, None
-    >>> uncontained(item, container, u'foo')
+    >>> uncontained(item, container, 'foo')
     >>> len(getEvents(IObjectRemovedEvent))
     1
     >>> len(getEvents(IObjectModifiedEvent))
     2
 
-    >>> item.__parent__, item.__name__ = None, u'bar'
-    >>> uncontained(item, container, u'foo')
+    >>> item.__parent__, item.__name__ = None, 'bar'
+    >>> uncontained(item, container, 'foo')
     >>> len(getEvents(IObjectRemovedEvent))
     1
     >>> len(getEvents(IObjectModifiedEvent))
@@ -670,10 +669,10 @@ def uncontained(object, container, name=None):
     >>> class Broken(object):
     ...     __Broken_state__ = {}
     >>> broken = Broken()
-    >>> broken.__Broken_state__['__name__'] = u'bar'
+    >>> broken.__Broken_state__['__name__'] = 'bar'
     >>> broken.__Broken_state__['__parent__'] = container
-    >>> container[u'bar'] = broken
-    >>> uncontained(broken, container, u'bar')
+    >>> container['bar'] = broken
+    >>> uncontained(broken, container, 'bar')
     >>> len(getEvents(IObjectRemovedEvent))
     2
 
@@ -709,7 +708,7 @@ def uncontained(object, container, name=None):
 
 
 @zope.interface.implementer(INameChooser)
-class NameChooser(object):
+class NameChooser:
 
     def __init__(self, context):
         self.context = context
@@ -736,14 +735,14 @@ def checkName(self, name, object):  # pylint:disable=redefined-builtin
         >>> NameChooser(container).checkName('foo', object())
         Traceback (most recent call last):
         ...
-        KeyError: u'The given name is already being used'
+        KeyError: 'The given name is already being used'
 
         A name must be a string or unicode string:
 
         >>> NameChooser(container).checkName(2, object())
         Traceback (most recent call last):
         ...
-        TypeError: ('Invalid name type', <type 'int'>)
+        TypeError: ('Invalid name type', <class 'int'>)
 
         A correct name returns True:
 
@@ -766,12 +765,12 @@ def checkName(self, name, object):  # pylint:disable=redefined-builtin
         >>> NameChooser(container).checkName('reserved', None)
         Traceback (most recent call last):
         ...
-        NameReserved: reserved
+        zope.container.interfaces.NameReserved: reserved
         """
 
         if isinstance(name, bytes):
             name = name.decode('ascii')
-        elif not isinstance(name, text_type):
+        elif not isinstance(name, str):
             raise TypeError("Invalid name type", type(name))
 
         if not name:
@@ -811,27 +810,27 @@ def chooseName(self, name, object):  # pylint:disable=redefined-builtin
 
         the suggested name is converted to unicode:
 
-        >>> NameChooser(container).chooseName(u'foobar', object())
-        u'foobar'
+        >>> NameChooser(container).chooseName('foobar', object())
+        'foobar'
 
         >>> NameChooser(container).chooseName(b'foobar', object())
-        u'foobar'
+        'foobar'
 
         If it already exists, a number is appended but keeps the same
         extension:
 
         >>> NameChooser(container).chooseName('foobar.old', object())
-        u'foobar-2.old'
+        'foobar-2.old'
 
         Bad characters are turned into dashes:
 
         >>> NameChooser(container).chooseName('foo/foo', object())
-        u'foo-foo'
+        'foo-foo'
 
         If no name is suggested, it is based on the object type:
 
         >>> NameChooser(container).chooseName('', [])
-        u'list'
+        'list'
 
         """
 
@@ -841,11 +840,11 @@ def chooseName(self, name, object):  # pylint:disable=redefined-builtin
         # allow
         if isinstance(name, bytes):
             name = name.decode('ascii')
-        if not isinstance(name, text_type):
+        if not isinstance(name, str):
             try:
-                name = text_type(name)
+                name = str(name)
             except Exception:
-                name = u''
+                name = ''
         name = name.replace('/', '-').lstrip('+@')
 
         if not name:
@@ -866,7 +865,7 @@ def chooseName(self, name, object):  # pylint:disable=redefined-builtin
         i = 1
         while n in container:
             i += 1
-            n = name + u'-' + str(i) + suffix
+            n = name + '-' + str(i) + suffix
 
         # Make sure the name is valid.  We may have started with something bad.
         self.checkName(n, object)
@@ -935,7 +934,7 @@ def __get__(self, inst, cls=None):
         return Provides(cls, provided)
 
 
-class DecoratedSecurityCheckerDescriptor(object):
+class DecoratedSecurityCheckerDescriptor:
     """
     Descriptor for a Decorator that provides a decorated security
     checker.
diff --git a/src/zope/container/directory.py b/src/zope/container/directory.py
index 540bf3e..fa64a70 100644
--- a/src/zope/container/directory.py
+++ b/src/zope/container/directory.py
@@ -23,7 +23,6 @@
 """
 __docformat__ = 'restructuredtext'
 
-from six.moves import map
 
 import zope.filerepresentation.interfaces
 from zope.component.interfaces import ISite
@@ -46,7 +45,7 @@ def noop(container):
 
 
 @implementer(zope.filerepresentation.interfaces.IDirectoryFactory)
-class Cloner(object):
+class Cloner:
     """
     `IContainer` to
     :class:`zope.filerepresentation.interfaces.IDirectoryFactory` adapter
@@ -71,7 +70,7 @@ def __call__(self, name):
         return removeSecurityProxy(self.context).__class__()
 
 
-class RootDirectoryFactory(object):
+class RootDirectoryFactory:
 
     def __init__(self, context):
         pass
@@ -80,7 +79,7 @@ def __call__(self, name):
         return Folder()
 
 
-class ReadDirectory(object):
+class ReadDirectory:
     """Adapter to provide a file-system rendition of folders."""
 
     def __init__(self, context):
diff --git a/src/zope/container/find.py b/src/zope/container/find.py
index 780e2fe..b585b5e 100644
--- a/src/zope/container/find.py
+++ b/src/zope/container/find.py
@@ -24,7 +24,7 @@
 
 
 @implementer(IFind)
-class FindAdapter(object):
+class FindAdapter:
     """Adapts :class:`zope.container.interfaces.IReadContainer`"""
 
     __used_for__ = IReadContainer
@@ -68,7 +68,7 @@ def _find_helper(id, object, container, id_filters, object_filters, result):
 
 
 @implementer(IIdFindFilter)
-class SimpleIdFindFilter(object):
+class SimpleIdFindFilter:
     """Filter objects by ID"""
 
     def __init__(self, ids):
@@ -80,7 +80,7 @@ def matches(self, id):
 
 
 @implementer(IObjectFindFilter)
-class SimpleInterfacesFindFilter(object):
+class SimpleInterfacesFindFilter:
     """Filter objects on the provided interfaces"""
 
     def __init__(self, *interfaces):
diff --git a/src/zope/container/folder.py b/src/zope/container/folder.py
index 6cce846..aced5de 100644
--- a/src/zope/container/folder.py
+++ b/src/zope/container/folder.py
@@ -35,7 +35,7 @@ def data(self, value):
         self._SampleContainer__data = value
 
     def __getstate__(self):
-        state = super(Folder, self).__getstate__()
+        state = super().__getstate__()
         data = state.pop('_SampleContainer__data')
         state['data'] = data
         return state
@@ -43,4 +43,4 @@ def __getstate__(self):
     def __setstate__(self, state):
         if 'data' in state and '_SampleContainer__data' not in state:
             state['_SampleContainer__data'] = state.pop('data')
-        super(Folder, self).__setstate__(state)
+        super().__setstate__(state)
diff --git a/src/zope/container/interfaces.py b/src/zope/container/interfaces.py
index 304c9e3..86bfa4e 100644
--- a/src/zope/container/interfaces.py
+++ b/src/zope/container/interfaces.py
@@ -223,8 +223,8 @@ class IReservedNames(Interface):
     """A sequence of names that are reserved for that container"""
 
     reservedNames = Set(
-        title=_(u'Reserved Names'),
-        description=_(u'Names that are not allowed for addable content'),
+        title=_('Reserved Names'),
+        description=_('Names that are not allowed for addable content'),
         required=True,
     )
 
diff --git a/src/zope/container/ordered.py b/src/zope/container/ordered.py
index d4a37d7..14acdd5 100644
--- a/src/zope/container/ordered.py
+++ b/src/zope/container/ordered.py
@@ -189,7 +189,7 @@ def __setitem__(self, key, object):
         >>> oc['foo'] = 'baz'
         Traceback (most recent call last):
         ...
-        KeyError: u'foo'
+        KeyError: 'foo'
         >>> oc._order
         ['foo', 'baz']
         """
diff --git a/src/zope/container/size.py b/src/zope/container/size.py
index 4b82af5..34457cd 100644
--- a/src/zope/container/size.py
+++ b/src/zope/container/size.py
@@ -1,4 +1,3 @@
-
 ##############################################################################
 #
 # Copyright (c) 2002 Zope Foundation and Contributors.
@@ -23,7 +22,7 @@
 
 
 @implementer(ISized)
-class ContainerSized(object):
+class ContainerSized:
     """
     Implements :class:`zope.size.interfaces.ISize` for
     :class:`zope.container.interfaces.IReadContainer`
diff --git a/src/zope/container/testing.py b/src/zope/container/testing.py
index 6a2c70d..316bb26 100644
--- a/src/zope/container/testing.py
+++ b/src/zope/container/testing.py
@@ -13,13 +13,10 @@
 ##############################################################################
 """Unit test logic for setting up and tearing down basic infrastructure
 """
-import re
-
 import zope.interface
 import zope.traversing.testing
 from zope.component.eventtesting import PlacelessSetup as EventPlacelessSetup
 from zope.component.testing import PlacelessSetup as CAPlacelessSetup
-from zope.testing import renormalizing
 from zope.traversing.interfaces import IContainmentRoot
 from zope.traversing.interfaces import ITraversable
 
@@ -32,35 +29,12 @@
 from zope.container.traversal import ContainerTraversable
 
 
-checker = renormalizing.RENormalizing([
-    # Python 3 unicode removed the "u".
-    (re.compile("u('.*?')"),
-     r"\1"),
-    (re.compile('u(".*?")'),
-     r"\1"),
-    # Python 3 renamed type to class.
-    (re.compile('<type '),
-     r"<class "),
-    # Python 3 adds module name to exceptions.
-    (re.compile("zope.interface.exceptions.Invalid"),
-     r"Invalid"),
-    (re.compile("zope.container.interfaces.InvalidContainerType"),
-     r"InvalidContainerType"),
-    (re.compile("zope.container.interfaces.InvalidItemType"),
-     r"InvalidItemType"),
-    (re.compile("zope.container.interfaces.NameReserved"),
-     r"NameReserved"),
-    (re.compile("zope.schema._bootstrapinterfaces.ConstraintNotSatisfied"),
-     r"ConstraintNotSatisfied"),
-])
-
-
 # XXX we would like to swap the names of the *PlacelessSetup classes
 # in here as that would seem to follow the convention better, but
 # unfortunately that would break compatibility with zope.app.testing
 # (which expects this PlacelessSetup) so it will have to wait.
 
-class PlacelessSetup(object):
+class PlacelessSetup:
 
     def setUp(self):
         component.provideAdapter(NameChooser, (IWriteContainer,), INameChooser)
@@ -107,9 +81,9 @@ def tearDown(self, docttesttest=None):
     def buildFolders(self):
         root = self.rootFolder = SampleContainer()
         zope.interface.directlyProvides(root, IContainmentRoot)
-        root[u'folder1'] = SampleContainer()
-        root[u'folder1'][u'folder1_1'] = SampleContainer()
-        root[u'folder1'][u'folder1_1'][u'folder1_1_1'] = SampleContainer()
-        root[u'folder2'] = SampleContainer()
-        root[u'folder2'][u'folder2_1'] = SampleContainer()
-        root[u'folder2'][u'folder2_1'][u'folder2_1_1'] = SampleContainer()
+        root['folder1'] = SampleContainer()
+        root['folder1']['folder1_1'] = SampleContainer()
+        root['folder1']['folder1_1']['folder1_1_1'] = SampleContainer()
+        root['folder2'] = SampleContainer()
+        root['folder2']['folder2_1'] = SampleContainer()
+        root['folder2']['folder2_1']['folder2_1_1'] = SampleContainer()
diff --git a/src/zope/container/tests/test_btree.py b/src/zope/container/tests/test_btree.py
index d2e6045..9e33342 100644
--- a/src/zope/container/tests/test_btree.py
+++ b/src/zope/container/tests/test_btree.py
@@ -154,11 +154,11 @@ def testCorrectLengthWhenAddingExistingItem(self):
         for bug #175388
         """
         bc = BTreeContainer()
-        bc[u'x'] = object()
+        bc['x'] = object()
         self.assertEqual(len(bc), 1)
-        bc[u'x'] = bc[u'x']
+        bc['x'] = bc['x']
         self.assertEqual(len(bc), 1)
-        self.assertEqual(list(bc), [u'x'])
+        self.assertEqual(list(bc), ['x'])
 
     def checkIterable(self, iterable):
         it = iter(iterable)
diff --git a/src/zope/container/tests/test_constraints.py b/src/zope/container/tests/test_constraints.py
index e437990..dd03174 100644
--- a/src/zope/container/tests/test_constraints.py
+++ b/src/zope/container/tests/test_constraints.py
@@ -13,10 +13,9 @@
 ##############################################################################
 """Container constraint tests
 """
+import doctest
 import unittest
 
-import six
-
 
 class TestUnaddableError(unittest.TestCase):
 
@@ -32,8 +31,8 @@ class TestCheckObject(unittest.TestCase):
     def test_non_container(self):
         from zope.container.constraints import checkObject
 
-        with six.assertRaisesRegex(
-                self, TypeError, "Container is not a valid Zope container."):
+        with self.assertRaisesRegex(
+                TypeError, "Container is not a valid Zope container."):
             checkObject({}, 'foo', 42)
 
 
@@ -43,7 +42,7 @@ def test_no_validate_on_parent(self):
         # Does nothing if no constraints are provided
         from zope.container.constraints import checkFactory
 
-        class Factory(object):
+        class Factory:
             def getInterfaces(self):
                 return {}
 
@@ -67,15 +66,10 @@ def test_raw_types_property(self):
 
 
 def test_suite():
-    import doctest
-
-    from zope.container import testing
     return unittest.TestSuite((
         unittest.defaultTestLoader.loadTestsFromName(__name__),
         doctest.DocTestSuite(
-            'zope.container.constraints',
-            checker=testing.checker),
+            'zope.container.constraints'),
         doctest.DocFileSuite(
-            '../constraints.rst',
-            checker=testing.checker),
+            '../constraints.rst'),
     ))
diff --git a/src/zope/container/tests/test_contained.py b/src/zope/container/tests/test_contained.py
index aad3e0f..42fbe1a 100644
--- a/src/zope/container/tests/test_contained.py
+++ b/src/zope/container/tests/test_contained.py
@@ -13,7 +13,6 @@
 ##############################################################################
 """Contained Tests
 """
-from __future__ import absolute_import
 
 import doctest
 import unittest
@@ -62,14 +61,13 @@ def test_basic_proxy_attribute_management_and_picklability(self):
     def test_declarations_on_ContainedProxy(self):
         # It is possible to make declarations on ContainedProxy objects.
         from persistent.interfaces import IPersistent
-
-        from zope.container.interfaces import IContained
+        from zope.location.interfaces import IContained
 
         class I1(zope.interface.Interface):  # pylint:disable=inherit-non-class
             pass
 
         @zope.interface.implementer(I1)
-        class C(object):
+        class C:
             pass
 
         c = C()
@@ -105,7 +103,7 @@ class I3(zope.interface.Interface):  # pylint:disable=inherit-non-class
 
     def test_ContainedProxy_instances_have_no_instance_dictionaries(self):
         # Make sure that proxies don't introduce extra instance dictionaries
-        class C(object):
+        class C:
             def __init__(self, x):
                 self.x = x
 
@@ -159,27 +157,27 @@ def test_checkName(self):
 
         # existing names
         self.assertRaises(KeyError, checkName, 'foo', object())
-        self.assertRaises(KeyError, checkName, u'foo', object())
+        self.assertRaises(KeyError, checkName, 'foo', object())
 
         # correct names
         self.assertEqual(True, checkName('2', object()))
-        self.assertEqual(True, checkName(u'2', object()))
+        self.assertEqual(True, checkName('2', object()))
         self.assertEqual(True, checkName('other', object()))
-        self.assertEqual(True, checkName(u'reserved', object()))
-        self.assertEqual(True, checkName(u'r\xe9served', object()))
+        self.assertEqual(True, checkName('reserved', object()))
+        self.assertEqual(True, checkName('r\xe9served', object()))
 
         # reserved names
         @zope.component.adapter(IContainer)
         @zope.interface.implementer(IReservedNames)
-        class ReservedNames(object):
+        class ReservedNames:
             def __init__(self, context):
-                self.reservedNames = set(('reserved', 'other'))
+                self.reservedNames = {'reserved', 'other'}
         zope.component.getSiteManager().registerAdapter(ReservedNames)
 
         self.assertRaises(NameReserved, checkName, 'reserved', object())
         self.assertRaises(NameReserved, checkName, 'other', object())
-        self.assertRaises(NameReserved, checkName, u'reserved', object())
-        self.assertRaises(NameReserved, checkName, u'other', object())
+        self.assertRaises(NameReserved, checkName, 'reserved', object())
+        self.assertRaises(NameReserved, checkName, 'other', object())
 
     def test_chooseName(self):
         container = SampleContainer()
@@ -188,39 +186,37 @@ def test_chooseName(self):
 
         # correct name without changes
         self.assertEqual(nc.chooseName('foobar.rst', None),
-                         u'foobar.rst')
-        self.assertEqual(nc.chooseName(u'\xe9', None),
-                         u'\xe9')
+                         'foobar.rst')
+        self.assertEqual(nc.chooseName('\xe9', None),
+                         '\xe9')
 
         # automatically modified named
         self.assertEqual(nc.chooseName('foo.old.rst', None),
-                         u'foo.old-2.rst')
+                         'foo.old-2.rst')
         self.assertEqual(nc.chooseName('+@+@foo.old.rst', None),
-                         u'foo.old-2.rst')
+                         'foo.old-2.rst')
         self.assertEqual(nc.chooseName('+@+@foo/foo+@', None),
-                         u'foo-foo+@')
+                         'foo-foo+@')
 
         # empty name
-        self.assertEqual(nc.chooseName('', None), u'NoneType')
-        self.assertEqual(nc.chooseName('@+@', []), u'list')
+        self.assertEqual(nc.chooseName('', None), 'NoneType')
+        self.assertEqual(nc.chooseName('@+@', []), 'list')
 
         # if the name is not a string it is converted
-        self.assertEqual(nc.chooseName(None, None), u'None')
-        self.assertEqual(nc.chooseName(2, None), u'2')
-        self.assertEqual(nc.chooseName([], None), u'[]')
+        self.assertEqual(nc.chooseName(None, None), 'None')
+        self.assertEqual(nc.chooseName(2, None), '2')
+        self.assertEqual(nc.chooseName([], None), '[]')
         container['None'] = 'something'
-        self.assertEqual(nc.chooseName(None, None), u'None-2')
+        self.assertEqual(nc.chooseName(None, None), 'None-2')
         container['None-2'] = 'something'
-        self.assertEqual(nc.chooseName(None, None), u'None-3')
+        self.assertEqual(nc.chooseName(None, None), 'None-3')
 
-        # even if the given name cannot be converted to unicode
-        class BadBoy(object):
-            def __unicode__(self):
+        # even if the given name cannot be converted to str
+        class BadBoy:
+            def __str__(self):
                 raise Exception
-            # Py3: Support
-            __str__ = __unicode__
 
-        self.assertEqual(nc.chooseName(BadBoy(), set()), u'set')
+        self.assertEqual(nc.chooseName(BadBoy(), set()), 'set')
 
 
 class TestFunctions(unittest.TestCase):
@@ -261,6 +257,5 @@ def test_suite():
     suite = unittest.defaultTestLoader.loadTestsFromName(__name__)
     suite.addTest(doctest.DocTestSuite(
         'zope.container.contained',
-        setUp=testing.setUp, tearDown=testing.tearDown,
-        checker=testing.checker))
+        setUp=testing.setUp, tearDown=testing.tearDown))
     return suite
diff --git a/src/zope/container/tests/test_containertraversable.py b/src/zope/container/tests/test_containertraversable.py
index f3bfe0c..50ff4d9 100644
--- a/src/zope/container/tests/test_containertraversable.py
+++ b/src/zope/container/tests/test_containertraversable.py
@@ -13,12 +13,9 @@
 ##############################################################################
 """Container Traverser tests.
 """
-from __future__ import absolute_import
 
 import unittest
 
-import six
-
 from zope.interface import implementer
 from zope.testing.cleanup import CleanUp
 from zope.traversing.interfaces import TraversalError
@@ -28,14 +25,14 @@
 
 
 @implementer(IContainer)
-class Container(object):
+class Container:
 
     def __init__(self, attrs=None, objs=None):
-        for attr, value in six.iteritems(attrs or {}):
+        for attr, value in (attrs or {}).items():
             setattr(self, attr, value)
 
         self.__objs = {}
-        for name, value in six.iteritems(objs or {}):
+        for name, value in (objs or {}).items():
             self.__objs[name] = value
 
     def get(self, name, default=None):
@@ -58,14 +55,14 @@ def testAttr(self):
     def test_unicode_obj(self):
         # test traversal with unicode
         voila = Container()
-        c = Container({}, {u'voil\xe0': voila})
-        self.assertIs(ContainerTraversable(c).traverse(u'voil\xe0', []),
+        c = Container({}, {'voil\xe0': voila})
+        self.assertIs(ContainerTraversable(c).traverse('voil\xe0', []),
                       voila)
 
     def test_unicode_attr(self):
         c = Container()
         with self.assertRaises(TraversalError):
-            ContainerTraversable(c).traverse(u'voil\xe0', [])
+            ContainerTraversable(c).traverse('voil\xe0', [])
 
 
 def test_suite():
diff --git a/src/zope/container/tests/test_containertraverser.py b/src/zope/container/tests/test_containertraverser.py
index e346bec..c2d9a91 100644
--- a/src/zope/container/tests/test_containertraverser.py
+++ b/src/zope/container/tests/test_containertraverser.py
@@ -31,7 +31,7 @@
 
 
 @implementer(IReadContainer)
-class TestContainer(object):
+class TestContainer:
 
     def __init__(self, **kw):
         for name, value in kw.items():
@@ -48,7 +48,7 @@ def __getitem__(self, name):
         return o
 
 
-class View(object):
+class View:
     def __init__(self, context, request):
         self.context = context
         self.request = request
@@ -65,7 +65,7 @@ def _getContainer(self, **kw):
         return TestContainer(**kw)
 
     def setUp(self):
-        super(TraverserTest, self).setUp()
+        super().setUp()
         # Create a small object tree
         self.container = self._getContainer()
         self.subcontainer = self._getContainer(Foo=self.container)
diff --git a/src/zope/container/tests/test_dependencies.py b/src/zope/container/tests/test_dependencies.py
index f3290ce..e96bfe0 100644
--- a/src/zope/container/tests/test_dependencies.py
+++ b/src/zope/container/tests/test_dependencies.py
@@ -23,7 +23,7 @@ def test_zcml_can_load(self):
         request = TestRequest()
 
         @implementer(IItemContainer)
-        class SampleItemContainer(object):
+        class SampleItemContainer:
             pass
 
         sampleitemcontainer = SampleItemContainer()
@@ -33,7 +33,7 @@ class SampleItemContainer(object):
         self.assertTrue(res.context is sampleitemcontainer)
 
         @implementer(ISimpleReadContainer)
-        class SampleSimpleReadContainer(object):
+        class SampleSimpleReadContainer:
             pass
 
         samplesimplereadcontainer = SampleSimpleReadContainer()
@@ -41,13 +41,3 @@ class SampleSimpleReadContainer(object):
             (samplesimplereadcontainer, request), IBrowserPublisher)
         self.assertTrue(isinstance(res, ItemTraverser))
         self.assertTrue(res.context is samplesimplereadcontainer)
-
-
-def test_suite():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(ZCMLDependencies))
-    return suite
-
-
-if __name__ == '__main__':
-    unittest.main()
diff --git a/src/zope/container/tests/test_directory.py b/src/zope/container/tests/test_directory.py
index 518c780..179d9ad 100644
--- a/src/zope/container/tests/test_directory.py
+++ b/src/zope/container/tests/test_directory.py
@@ -21,7 +21,7 @@
 from zope.container import testing
 
 
-class Directory(object):
+class Directory:
     a = None
 
 
diff --git a/src/zope/container/tests/test_find.py b/src/zope/container/tests/test_find.py
index 9eebb86..3315aa8 100644
--- a/src/zope/container/tests/test_find.py
+++ b/src/zope/container/tests/test_find.py
@@ -27,7 +27,7 @@
 
 
 @implementer(IReadContainer)
-class FakeContainer(object):
+class FakeContainer:
 
     def __init__(self, id, objects):
         self._id = id
@@ -53,7 +53,7 @@ class FakeInterfaceSpam(Interface):
 
 
 @implementer(IObjectFindFilter)
-class TestObjectFindFilter(object):
+class TestObjectFindFilter:
 
     def __init__(self, count):
         self._count = count
diff --git a/src/zope/container/tests/test_folder.py b/src/zope/container/tests/test_folder.py
index fdd2686..f8f74bc 100644
--- a/src/zope/container/tests/test_folder.py
+++ b/src/zope/container/tests/test_folder.py
@@ -1,6 +1,5 @@
 import pickle
 from unittest import TestCase
-from unittest import makeSuite
 
 from zope.container.folder import Folder
 from zope.container.tests.test_icontainer import TestSampleContainer
@@ -25,7 +24,3 @@ def testPickleCompatibility(self):
 
         folder_clone = pickle.loads(pickle.dumps(folder))
         self.assertEqual(folder_clone['a'], folder['a'])
-
-
-def test_suite():
-    return makeSuite(Test)
diff --git a/src/zope/container/tests/test_icontainer.py b/src/zope/container/tests/test_icontainer.py
index fc724e3..011202f 100644
--- a/src/zope/container/tests/test_icontainer.py
+++ b/src/zope/container/tests/test_icontainer.py
@@ -14,8 +14,6 @@
 """Test the IContainer interface.
 """
 from unittest import TestCase
-from unittest import main
-from unittest import makeSuite
 
 from zope.interface.verify import verifyObject
 
@@ -155,9 +153,9 @@ def test_bytes_keys_converted_to_unicode(self):
         # https://github.com/zopefoundation/zope.container/issues/17
         container = self.makeTestObject()
         container[b'abc'] = 1
-        self.assertIn(u'abc', container)
-        del container[u'abc']
-        self.assertNotIn(u'abc', container)
+        self.assertIn('abc', container)
+        del container['abc']
+        self.assertNotIn('abc', container)
 
     def test_exception_in_subscriber_leaves_item_in_place(self):
         # Now register an event subscriber to object added events that
@@ -355,11 +353,3 @@ def getUnknownKey(self):
 
     def getBadKeyTypes(self):
         return [None, [b'foo'], 1, b'\xf3abc']
-
-
-def test_suite():
-    return makeSuite(TestSampleContainer)
-
-
-if __name__ == '__main__':
-    main(defaultTest='test_suite')
diff --git a/src/zope/container/tests/test_ordered.py b/src/zope/container/tests/test_ordered.py
index a836b2b..b008e48 100644
--- a/src/zope/container/tests/test_ordered.py
+++ b/src/zope/container/tests/test_ordered.py
@@ -20,7 +20,6 @@
 from zope.component.eventtesting import getEvents
 
 from zope.container import testing
-from zope.container._compat import text_type
 from zope.container.tests.test_icontainer import TestSampleContainer
 
 
@@ -96,7 +95,7 @@ def test_order_adding_none(self):
     def test_order_updateOrder_bytes(self):
         # https://github.com/zopefoundation/zope.container/issues/21
         from zope.container.ordered import OrderedContainer
-        keys = [u'a', u'b']
+        keys = ['a', 'b']
         oc = OrderedContainer()
         oc[keys[0]] = 0
         oc[keys[1]] = 1
@@ -107,7 +106,7 @@ def test_order_updateOrder_bytes(self):
         oc.updateOrder((b'b', b'a'))
         # still produces text keys
         self.assertEqual(list(reversed(keys)), oc.keys())
-        self.assertIsInstance(oc.keys()[0], text_type)
+        self.assertIsInstance(oc.keys()[0], str)
 
 
 def test_suite():
@@ -116,7 +115,6 @@ def test_suite():
     ])
     suite.addTest(DocTestSuite("zope.container.ordered",
                                setUp=testing.setUp,
-                               tearDown=testing.tearDown,
-                               checker=testing.checker))
+                               tearDown=testing.tearDown))
 
     return suite
diff --git a/src/zope/container/tests/test_size.py b/src/zope/container/tests/test_size.py
index e62873c..088b1ea 100644
--- a/src/zope/container/tests/test_size.py
+++ b/src/zope/container/tests/test_size.py
@@ -22,7 +22,7 @@
 
 
 @implementer(IContainer)
-class DummyContainer(object):
+class DummyContainer:
 
     def __init__(self, numitems):
         self._numitems = numitems
@@ -43,7 +43,7 @@ def testEmptyContainer(self):
         obj = DummyContainer(0)
         sized = ContainerSized(obj)
         self.assertEqual(sized.sizeForSorting(), ('item', 0))
-        self.assertEqual(sized.sizeForDisplay(), u'${items} items')
+        self.assertEqual(sized.sizeForDisplay(), '${items} items')
         self.assertEqual(sized.sizeForDisplay().mapping['items'], '0')
 
     def testOneItem(self):
@@ -51,14 +51,14 @@ def testOneItem(self):
         obj = DummyContainer(1)
         sized = ContainerSized(obj)
         self.assertEqual(sized.sizeForSorting(), ('item', 1))
-        self.assertEqual(sized.sizeForDisplay(), u'1 item')
+        self.assertEqual(sized.sizeForDisplay(), '1 item')
 
     def testSeveralItems(self):
         from zope.container.size import ContainerSized
         obj = DummyContainer(2)
         sized = ContainerSized(obj)
         self.assertEqual(sized.sizeForSorting(), ('item', 2))
-        self.assertEqual(sized.sizeForDisplay(), u'${items} items')
+        self.assertEqual(sized.sizeForDisplay(), '${items} items')
         self.assertEqual(sized.sizeForDisplay().mapping['items'], '2')
 
 
diff --git a/src/zope/container/traversal.py b/src/zope/container/traversal.py
index da018b3..02db8c8 100644
--- a/src/zope/container/traversal.py
+++ b/src/zope/container/traversal.py
@@ -15,7 +15,6 @@
 """
 __docformat__ = 'restructuredtext'
 
-from six.moves import map
 
 from zope.component import ComponentLookupError
 from zope.component import getSiteManager
@@ -38,7 +37,7 @@
 # can be used for multiple view types.
 
 @implementer(IBrowserPublisher, IXMLRPCPublisher)
-class ContainerTraverser(object):
+class ContainerTraverser:
     """A traverser that knows how to look up objects by name in a container."""
 
     __used_for__ = ISimpleReadContainer
@@ -95,7 +94,7 @@ def publishTraverse(self, request, name):
 
 
 @implementer(ITraversable)
-class ContainerTraversable(object):
+class ContainerTraversable:
     """Traverses containers via `getattr` and `get`."""
 
     __used_for__ = IReadContainer