Config with c code template 831a34f5 (#91)

* Drop support for Python 2.7, 3.5, 3.6.

39 files changed, 400 insertions, 966 deletions

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 9a7f8c9..9551c7b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -96,11 +96,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "2.7"
-          - "3.5"
-          - "pypy-2.7"
           - "pypy-3.7"
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"
@@ -109,11 +105,7 @@ jobs:
         os: [ubuntu-20.04, macos-latest]
         exclude:
           - os: macos-latest
-            python-version: "pypy-2.7"
-          - os: macos-latest
             python-version: "pypy-3.7"
-          - os: macos-latest
-            python-version: "3.5"
 
     steps:
       - name: checkout
@@ -141,16 +133,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-pip-
 
-      - name: Install Build Dependencies (PyPy2)
-        if: >
-          startsWith(matrix.python-version, 'pypy-2.7')
-        run: |
-          pip install -U pip
-          pip install -U setuptools wheel twine "cffi != 1.15.1"
-          pip install -U zope.proxy
-      - name: Install Build Dependencies (other Python versions)
-        if: >
-          !startsWith(matrix.python-version, 'pypy-2.7')
+      - name: Install Build Dependencies
         run: |
           pip install -U pip
           pip install -U setuptools wheel twine cffi
@@ -160,9 +143,6 @@ jobs:
         if: >
           startsWith(runner.os, 'Mac')
           && !(startsWith(matrix.python-version, 'pypy')
-               || matrix.python-version == '2.7'
-               || matrix.python-version == '3.5'
-               || matrix.python-version == '3.6'
                || matrix.python-version == '3.7')
         env:
           MACOSX_DEPLOYMENT_TARGET: 10.9
@@ -177,9 +157,6 @@ jobs:
         if: >
           startsWith(runner.os, 'Mac')
           && !(startsWith(matrix.python-version, 'pypy')
-               || matrix.python-version == '2.7'
-               || matrix.python-version == '3.5'
-               || matrix.python-version == '3.6'
                || matrix.python-version == '3.7')
         env:
           MACOSX_DEPLOYMENT_TARGET: 11.0
@@ -194,9 +171,6 @@ jobs:
         if: >
           !startsWith(runner.os, 'Mac')
           || startsWith(matrix.python-version, 'pypy')
-          || matrix.python-version == '2.7'
-          || matrix.python-version == '3.5'
-          || matrix.python-version == '3.6'
           || matrix.python-version == '3.7'
         run: |
           # Next, build the wheel *in place*. This helps ccache, and also lets us cache the configure
@@ -207,7 +181,6 @@ jobs:
       - name: Install zope.security and dependencies
         run: |
           # Install to collect dependencies into the (pip) cache.
-          pip install -U 'faulthandler; python_version == "2.7" and platform_python_implementation == "CPython"'
           pip install .[test]
 
       - name: Check zope.security build
@@ -225,9 +198,6 @@ jobs:
         if: >
           startsWith(runner.os, 'Mac')
           && !(startsWith(matrix.python-version, 'pypy')
-               || matrix.python-version == '2.7'
-               || matrix.python-version == '3.5'
-               || matrix.python-version == '3.6'
                || matrix.python-version == '3.7')
         uses: actions/upload-artifact@v3
         with:
@@ -264,11 +234,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "2.7"
-          - "3.5"
-          - "pypy-2.7"
           - "pypy-3.7"
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"
@@ -277,11 +243,7 @@ jobs:
         os: [ubuntu-20.04, macos-latest]
         exclude:
           - os: macos-latest
-            python-version: "pypy-2.7"
-          - os: macos-latest
             python-version: "pypy-3.7"
-          - os: macos-latest
-            python-version: "3.5"
 
     steps:
       - name: checkout
@@ -318,7 +280,6 @@ jobs:
         run: |
           pip install -U wheel setuptools
           pip install -U coverage
-          pip install -U 'faulthandler; python_version == "2.7" and platform_python_implementation == "CPython"'
           pip install -U 'cffi; platform_python_implementation == "CPython"'
           # Unzip into src/ so that testrunner can find the .so files
           # when we ask it to load tests from that directory. This
@@ -498,8 +459,6 @@ jobs:
         # An alternate way to do this is to run the container directly with a uses:
         # and then the script runs inside it. That may work better with caching.
         # See https://github.com/pyca/bcrypt/blob/f6b5ee2eda76d077c531362ac65e16f045cf1f29/.github/workflows/wheel-builder.yml
-        # The 2010 image is the most recent spec that comes with Python 2.7,
-        # and only up through the tag 2021-02-06-3d322a5
         env:
           DOCKER_IMAGE: quay.io/pypa/${{ matrix.image }}
         run: |
diff --git a/.manylinux-install.sh b/.manylinux-install.sh
index 8e5bb9c..8f736da 100755
--- a/.manylinux-install.sh
+++ b/.manylinux-install.sh
@@ -28,9 +28,6 @@ yum -y install libffi-devel
 
 tox_env_map() {
     case $1 in
-        *"cp27"*) echo 'py27';;
-        *"cp35"*) echo 'py35';;
-        *"cp36"*) echo 'py36';;
         *"cp37"*) echo 'py37';;
         *"cp38"*) echo 'py38';;
         *"cp39"*) echo 'py39';;
@@ -43,10 +40,7 @@ tox_env_map() {
 # Compile wheels
 for PYBIN in /opt/python/*/bin; do
     if \
-       [[ "${PYBIN}" == *"cp27"* ]] || \
-       [[ "${PYBIN}" == *"cp35"* ]] || \
        [[ "${PYBIN}" == *"cp311"* ]] || \
-       [[ "${PYBIN}" == *"cp36"* ]] || \
        [[ "${PYBIN}" == *"cp37"* ]] || \
        [[ "${PYBIN}" == *"cp38"* ]] || \
        [[ "${PYBIN}" == *"cp39"* ]] || \
diff --git a/.meta.toml b/.meta.toml
index e6bc2a1..28cb8fe 100644
--- a/.meta.toml
+++ b/.meta.toml
@@ -2,14 +2,13 @@
 # https://github.com/zopefoundation/meta/tree/master/config/c-code
 [meta]
 template = "c-code"
-commit-id = "342271a70d886e753e5cc629e8a81b3cfab692ac"
+commit-id = "46a3f3bc"
 
 [python]
 with-appveyor = true
 with-windows = false
 with-pypy = true
 with-future-python = false
-with-legacy-python = true
 with-docs = true
 with-sphinx-doctests = true
 with-macos = false
@@ -17,7 +16,7 @@ with-macos = false
 [tox]
 use-flake8 = true
 additional-envlist = [
-    "py27-watch, py37-watch",
+    "py37-watch, py311-watch",
     ]
 testenv-setenv = [
     "ZOPE_INTERFACE_STRICT_IRO=1",
@@ -48,8 +47,8 @@ additional-config = [
 
 [github-actions]
 additional-config = [
-    "- [\"2.7\",   \"py27-watch\"]",
     "- [\"3.7\",   \"py37-watch\"]",
+    "- [\"3.11\",  \"py311-watch\"]",
     ]
 additional-build-dependencies = [
     "zope.proxy",
diff --git a/CHANGES.rst b/CHANGES.rst
index 66223e8..0e86f75 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,10 +2,10 @@
  Changes
 =========
 
-5.9 (unreleased)
+6.0 (unreleased)
 ================
 
-- Nothing changed yet.
+- Drop support for Python 2.7, 3.5, 3.6.
 
 
 5.8 (2022-11-30)
diff --git a/appveyor.yml b/appveyor.yml
index f798e96..6344764 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -9,9 +9,6 @@ environment:
   ZOPE_INTERFACE_STRICT_IRO: 1
 
   matrix:
-    - python: 27-x64
-    - python: 35-x64
-    - python: 36-x64
     - python: 37-x64
     - python: 38-x64
     - python: 39-x64
diff --git a/setup.cfg b/setup.cfg
index 5d7fd75..916fb60 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,7 +1,7 @@
 # Generated from:
 # https://github.com/zopefoundation/meta/tree/master/config/c-code
 [bdist_wheel]
-universal = 1
+universal = 0
 
 [zest.releaser]
 create-wheel = no
diff --git a/setup.py b/setup.py
index b1d224f..4f42035 100644
--- a/setup.py
+++ b/setup.py
@@ -69,7 +69,7 @@ def read(*rnames):
 # Sniff the location of the headers in the package distribution
 
 
-class ModuleHeaderDir(object):
+class ModuleHeaderDir:
 
     def __init__(self, require_spec, where='../..'):
         # By default, assume top-level pkg has the same name as the dist.
@@ -129,7 +129,7 @@ TESTS_REQUIRE = [
 
 
 setup(name='zope.security',
-      version='5.9.dev0',
+      version='6.0.dev0',
       author='Zope Foundation and Contributors',
       author_email='zope-dev@zope.org',
       description='Zope Security Framework',
@@ -145,11 +145,7 @@ setup(name='zope.security',
           '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',
@@ -164,10 +160,10 @@ setup(name='zope.security',
       ],
       url='http://github.com/zopefoundation/zope.security',
       project_urls={
-        'Documentation': 'https://zopesecurity.readthedocs.io',
-        'Issue Tracker': ('https://github.com/zopefoundation'
-                          '/zope.security/issues'),
-        'Sources': 'https://github.com/zopefoundation/zope.security',
+          'Documentation': 'https://zopesecurity.readthedocs.io',
+          'Issue Tracker': ('https://github.com/zopefoundation'
+                            '/zope.security/issues'),
+          'Sources': 'https://github.com/zopefoundation/zope.security',
       },
       license='ZPL 2.1',
       packages=find_packages('src'),
@@ -178,7 +174,7 @@ setup(name='zope.security',
           'build_ext': optional_build_ext,
       },
       ext_modules=ext_modules,
-      python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*',
+      python_requires='>=3.7',
       install_requires=[
           'setuptools',
           'zope.component',
diff --git a/src/zope/security/_compat.py b/src/zope/security/_compat.py
index 99f0d75..0d95d9f 100644
--- a/src/zope/security/_compat.py
+++ b/src/zope/security/_compat.py
@@ -15,32 +15,14 @@
 """
 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)
 
-if sys.version_info[0] < 3:  # pragma: no cover
 
-    CLASS_TYPES = (type, types.ClassType)
-    _BUILTINS = '__builtin__'
-
-    PYTHON3 = False
-    PYTHON2 = True
-
-else:  # pragma: no cover
-
-    CLASS_TYPES = (type,)
-    _BUILTINS = 'builtins'
-
-    PYTHON3 = True
-    PYTHON2 = False
-
-
-class implementer_if_needed(object):
+class implementer_if_needed:
     # Helper to make sure we don't redundantly implement interfaces
     # already inherited. Doing so tends to produce problems with the
     # C3 order. Even though here we could easily statically determine
diff --git a/src/zope/security/_definitions.py b/src/zope/security/_definitions.py
index f1d0176..efbfc7a 100644
--- a/src/zope/security/_definitions.py
+++ b/src/zope/security/_definitions.py
@@ -24,10 +24,10 @@ thread_local = threading.local()
 
 
 @zope.interface.implementer(interfaces.ISystemPrincipal)
-class SystemUser(object):
-    id = u'zope.security.management.system_user'
-    title = u'System'
-    description = u''
+class SystemUser:
+    id = 'zope.security.management.system_user'
+    title = 'System'
+    description = ''
 
 
 system_user = SystemUser()
diff --git a/src/zope/security/_proxy.c b/src/zope/security/_proxy.c
index 04321d7..ce42c54 100644
--- a/src/zope/security/_proxy.c
+++ b/src/zope/security/_proxy.c
@@ -19,53 +19,29 @@ Security Proxy Implementation
 
 static PyObject *__class__str = 0, *__name__str = 0, *__module__str = 0;
 
-// Compatibility with Python 2
-#if PY_MAJOR_VERSION < 3
-  #define IS_STRING PyString_Check
-
-  #define MAKE_STRING(name) PyString_AS_STRING(name)
-
-  #define FROM_STRING PyString_FromString
-
-  #define FROM_STRING_FORMAT PyString_FromFormat
+#define PyInt_FromLong PyLong_FromLong
 
-  #define INTERN PyString_InternFromString
+#define IS_STRING PyUnicode_Check
 
-  #define MOD_ERROR_VAL
+#define MAKE_STRING(name) PyBytes_AS_STRING( \
+        PyUnicode_AsUTF8String(name))
 
-  #define MOD_SUCCESS_VAL(val)
-
-  #define MOD_INIT(name) void init##name(void)
-
-  #define MOD_DEF(ob, name, doc, methods) \
-          ob = Py_InitModule3(name, methods, doc);
-
-#else
+#define FROM_STRING PyUnicode_FromString
 
-  #define PyInt_FromLong PyLong_FromLong
+#define FROM_STRING_FORMAT PyUnicode_FromFormat
 
-  #define IS_STRING PyUnicode_Check
+#define INTERN PyUnicode_InternFromString
 
-  #define MAKE_STRING(name) PyBytes_AS_STRING( \
-          PyUnicode_AsUTF8String(name))
+#define MOD_ERROR_VAL NULL
 
-  #define FROM_STRING PyUnicode_FromString
+#define MOD_SUCCESS_VAL(val) val
 
-  #define FROM_STRING_FORMAT PyUnicode_FromFormat
+#define MOD_INIT(name) PyMODINIT_FUNC PyInit_##name(void)
 
-  #define INTERN PyUnicode_InternFromString
-
-  #define MOD_ERROR_VAL NULL
-
-  #define MOD_SUCCESS_VAL(val) val
-
-  #define MOD_INIT(name) PyMODINIT_FUNC PyInit_##name(void)
-
-  #define MOD_DEF(ob, name, doc, methods) \
-          static struct PyModuleDef moduledef = { \
-            PyModuleDef_HEAD_INIT, name, doc, -1, methods, }; \
-          ob = PyModule_Create(&moduledef);
-#endif
+#define MOD_DEF(ob, name, doc, methods) \
+        static struct PyModuleDef moduledef = { \
+          PyModuleDef_HEAD_INIT, name, doc, -1, methods, }; \
+        ob = PyModule_Create(&moduledef);
 
 #define DECLARE_STRING(N) static PyObject *str_##N
 
@@ -931,16 +907,9 @@ static PyTypeObject SecurityProxyType = {
     (getattrofunc)proxy_getattro,             /* tp_getattro */
     (setattrofunc)proxy_setattro,             /* tp_setattro */
     0,                                        /* tp_as_buffer */
-#if PY_MAJOR_VERSION < 3
     Py_TPFLAGS_DEFAULT |
-    Py_TPFLAGS_BASETYPE |
-    Py_TPFLAGS_CHECKTYPES |
-    Py_TPFLAGS_HAVE_GC,                       /* tp_flags */
-#else // Py_TPFLAGS_CHECKTYPES is always true in Python 3 and removed.
-        Py_TPFLAGS_DEFAULT |
-        Py_TPFLAGS_HAVE_GC |
-        Py_TPFLAGS_BASETYPE,                    /* tp_flags */
-#endif
+    Py_TPFLAGS_HAVE_GC |
+    Py_TPFLAGS_BASETYPE,                      /* tp_flags */
     proxy_doc,                                /* tp_doc */
     (traverseproc)proxy_traverse,             /* tp_traverse */
     0,                                        /* tp_clear */
diff --git a/src/zope/security/_zope_security_checker.c b/src/zope/security/_zope_security_checker.c
index 63b0548..23d7fb9 100644
--- a/src/zope/security/_zope_security_checker.c
+++ b/src/zope/security/_zope_security_checker.c
@@ -17,55 +17,32 @@ static PyObject *_checkers, *_defaultChecker, *_available_by_default, *NoProxy;
 static PyObject *Proxy, *thread_local, *CheckerPublic;
 static PyObject *ForbiddenAttribute, *Unauthorized;
 
-// Compatibility with Python 2
-#if PY_MAJOR_VERSION < 3
-  #define IS_STRING PyString_Check
 
-  #define MAKE_STRING(name) PyString_AS_STRING(name)
+#define PyInt_FromLong PyLong_FromLong
 
-  #define FROM_STRING PyString_FromString
+#define IS_STRING PyUnicode_Check
 
-  #define FROM_STRING_FORMAT PyString_FromFormat
+#define MAKE_STRING(name) PyBytes_AS_STRING( \
+        PyUnicode_AsUTF8String(name))
 
-  #define INTERN PyString_InternFromString
+#define FROM_STRING PyUnicode_FromString
 
-  #define MOD_ERROR_VAL
+#define FROM_STRING_FORMAT PyUnicode_FromFormat
 
-  #define MOD_SUCCESS_VAL(val)
+#define INTERN PyUnicode_InternFromString
 
-  #define MOD_INIT(name) void init##name(void)
+#define MOD_ERROR_VAL NULL
 
-  #define MOD_DEF(ob, name, doc, methods) \
-          ob = Py_InitModule3(name, methods, doc);
+#define MOD_SUCCESS_VAL(val) val
 
-#else
+#define MOD_INIT(name) PyMODINIT_FUNC PyInit_##name(void)
 
-  #define PyInt_FromLong PyLong_FromLong
+#define MOD_DEF(ob, name, doc, methods) \
+        static struct PyModuleDef moduledef = { \
+          PyModuleDef_HEAD_INIT, name, doc, -1, methods, }; \
+        ob = PyModule_Create(&moduledef);
 
-  #define IS_STRING PyUnicode_Check
-
-  #define MAKE_STRING(name) PyBytes_AS_STRING( \
-          PyUnicode_AsUTF8String(name))
-
-  #define FROM_STRING PyUnicode_FromString
-
-  #define FROM_STRING_FORMAT PyUnicode_FromFormat
-
-  #define INTERN PyUnicode_InternFromString
-
-  #define MOD_ERROR_VAL NULL
-
-  #define MOD_SUCCESS_VAL(val) val
-
-  #define MOD_INIT(name) PyMODINIT_FUNC PyInit_##name(void)
-
-  #define MOD_DEF(ob, name, doc, methods) \
-          static struct PyModuleDef moduledef = { \
-            PyModuleDef_HEAD_INIT, name, doc, -1, methods, }; \
-          ob = PyModule_Create(&moduledef);
-
-  #define statichere static
-#endif
+#define statichere static
 
 #define DECLARE_STRING(N) static PyObject *str_##N
 
diff --git a/src/zope/security/adapter.py b/src/zope/security/adapter.py
index 0f5bc84..1905710 100644
--- a/src/zope/security/adapter.py
+++ b/src/zope/security/adapter.py
@@ -45,7 +45,7 @@ def assertLocation(adapter, parent):
     return adapter
 
 
-class LocatingTrustedAdapterFactory(object):
+class LocatingTrustedAdapterFactory:
     """
     Adapt an adapter factory to provide trusted and (locatable) adapters.
 
@@ -109,7 +109,7 @@ class TrustedAdapterFactory(LocatingTrustedAdapterFactory):
         return self._customizeUnprotected(adapter, context)
 
 
-class LocatingUntrustedAdapterFactory(object):
+class LocatingUntrustedAdapterFactory:
     """
     Adapt an adapter factory to provide locatable untrusted adapters
 
diff --git a/src/zope/security/checker.py b/src/zope/security/checker.py
index ae8ab5a..db7a167 100644
--- a/src/zope/security/checker.py
+++ b/src/zope/security/checker.py
@@ -75,9 +75,7 @@ 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
@@ -109,7 +107,7 @@ def ProxyFactory(object, checker=None):
 
     The proxy checker is looked up if not provided.
     """
-    if type(object) is Proxy:
+    if isinstance(object, Proxy):
         if checker is None or checker is getChecker(object):
             return object
         else:
@@ -197,7 +195,7 @@ def canAccess(obj, name):
 
 
 @implementer(INameBasedChecker)
-class CheckerPy(object):
+class CheckerPy:
     """
     The Python reference implementation of
     :class:`zope.security.interfaces.INameBasedChecker`.
@@ -280,7 +278,7 @@ class CheckerPy(object):
 
     def proxy(self, value):
         'See IChecker'
-        if type(value) is Proxy:
+        if isinstance(value, Proxy):
             return value
         checker = getattr(value, '__Security_checker__', None)
         if checker is None:
@@ -295,7 +293,7 @@ Checker = CheckerPy  # in case no C optimizations
 
 
 # Helper class for __traceback_supplement__
-class TracebackSupplement(object):
+class TracebackSupplement:
 
     def __init__(self, obj):
         self.obj = obj
@@ -305,7 +303,7 @@ class TracebackSupplement(object):
         try:
             cls = self.obj.__class__
             if hasattr(cls, "__module__"):
-                s = "%s.%s" % (cls.__module__, cls.__name__)
+                s = "{}.{}".format(cls.__module__, cls.__name__)
             else:  # pragma: no cover XXX
                 s = str(cls.__name__)
             result.append("   - class: " + s)
@@ -314,7 +312,7 @@ class TracebackSupplement(object):
         try:
             cls = type(self.obj)
             if hasattr(cls, "__module__"):
-                s = "%s.%s" % (cls.__module__, cls.__name__)
+                s = "{}.{}".format(cls.__module__, cls.__name__)
             else:  # pragma: no cover XXX
                 s = str(cls.__name__)
             result.append("   - type: " + s)
@@ -323,7 +321,7 @@ class TracebackSupplement(object):
         return "\n".join(result)
 
 
-class Global(object):
+class Global:
     """A global object that behaves like a string.
 
     We want this to behave as a global, meaning it's pickled
@@ -342,8 +340,8 @@ class Global(object):
         return self.__name__
 
     def __repr__(self):
-        return "%s(%s,%s)" % (self.__class__.__name__,
-                              self.__name__, self.__module__)
+        return "{}({},{})".format(self.__class__.__name__,
+                                  self.__name__, self.__module__)
 
 
 CheckerPublic = Global('CheckerPublic')
@@ -412,7 +410,7 @@ def MultiChecker(specs):
     data = {}
 
     for spec in specs:
-        if type(spec) is tuple:
+        if isinstance(spec, tuple):
             names, permission_id = spec
             if IInterface.providedBy(names):
                 names = names.names(all=True)
@@ -470,7 +468,7 @@ def getCheckerForInstancesOf(class_):
     return _checkers.get(class_)
 
 
-DEFINABLE_TYPES = CLASS_TYPES + (types.ModuleType,)
+DEFINABLE_TYPES = (type, types.ModuleType)
 
 
 def defineChecker(type_, checker):
@@ -589,7 +587,7 @@ class CombinedChecker(Checker):
                 raise unauthorized_exception
 
 
-class CheckerLoggingMixin(object):
+class CheckerLoggingMixin:
     """
     Debugging mixin for checkers.
 
@@ -611,26 +609,26 @@ class CheckerLoggingMixin(object):
 
     def check(self, object, name):
         try:
-            super(CheckerLoggingMixin, self).check(object, name)
+            super().check(object, name)
             if self.verbosity > 1:
                 if name in _available_by_default:
                     self._log('[CHK] + Always available: %s on %r'
                               % (name, object), 2)
                 else:
                     self._log(
-                        '[CHK] + Granted: %s on %r' % (name, object), 2)
+                        '[CHK] + Granted: {} on {!r}'.format(name, object), 2)
         except Unauthorized:
             self._log(
-                '[CHK] - Unauthorized: %s on %r' % (name, object))
+                '[CHK] - Unauthorized: {} on {!r}'.format(name, object))
             raise
         except ForbiddenAttribute:
             self._log(
-                '[CHK] - Forbidden: %s on %r' % (name, object))
+                '[CHK] - Forbidden: {} on {!r}'.format(name, object))
             raise
 
     def check_getattr(self, object, name):
         try:
-            super(CheckerLoggingMixin, self).check(object, name)
+            super().check(object, name)
             if self.verbosity > 1:
                 if name in _available_by_default:
                     self._log(
@@ -642,28 +640,31 @@ class CheckerLoggingMixin(object):
                         % (name, object), 2)
         except Unauthorized:
             self._log(
-                '[CHK] - Unauthorized getattr: %s on %r' % (name, object))
+                '[CHK] - Unauthorized getattr: {} on {!r}'.format(name, object)
+            )
             raise
         except ForbiddenAttribute:
             self._log(
-                '[CHK] - Forbidden getattr: %s on %r' % (name, object))
+                '[CHK] - Forbidden getattr: {} on {!r}'.format(name, object))
             raise
 
     __setitem__ = check_getattr
 
     def check_setattr(self, object, name):
         try:
-            super(CheckerLoggingMixin, self).check_setattr(object, name)
+            super().check_setattr(object, name)
             if self.verbosity > 1:
                 self._log(
-                    '[CHK] + Granted setattr: %s on %r' % (name, object), 2)
+                    '[CHK] + Granted setattr: {} on {!r}'.format(
+                        name, object), 2)
         except Unauthorized:
             self._log(
-                '[CHK] - Unauthorized setattr: %s on %r' % (name, object))
+                '[CHK] - Unauthorized setattr: {} on {!r}'.format(
+                    name, object))
             raise
         except ForbiddenAttribute:
             self._log(
-                '[CHK] - Forbidden setattr: %s on %r' % (name, object))
+                '[CHK] - Forbidden setattr: {} on {!r}'.format(name, object))
             raise
 
 
@@ -784,14 +785,10 @@ _basic_types = {
     datetime.date: NoProxy,
     datetime.time: NoProxy,
     datetime.tzinfo: NoProxy,
+    type({}.values()): NoProxy,
+    type({}.keys()): NoProxy,
+    type({}.items()): NoProxy,
 }
-if PYTHON2:  # pragma: no cover
-    _basic_types[long] = NoProxy  # noqa: F821 undefined name 'long'
-    _basic_types[unicode] = NoProxy  # noqa: F821 undefined name 'unicode'
-else:
-    _basic_types[type({}.values())] = NoProxy
-    _basic_types[type({}.keys())] = NoProxy
-    _basic_types[type({}.items())] = NoProxy
 
 try:
     import pytz
@@ -819,12 +816,8 @@ BasicTypes_examples = {
     Message: Message('message', domain='hello')
 }
 
-if PYTHON2:  # pragma: no cover
-    BasicTypes_examples[unicode] = u'uabc'  # noqa: F821 undefined name
-    BasicTypes_examples[long] = long(65536)  # noqa: F821 undefined name
-
 
-class _Sequence(object):
+class _Sequence:
     def __len__(self):
         raise NotImplementedError()
 
@@ -891,8 +884,8 @@ _default_checkers = {
     type(().__repr__): _callableChecker,
     type: _typeChecker,
     types.ModuleType: lambda module: _checkers.get(module, _namedChecker),
-    type(iter([])): _iteratorChecker,  # Same types in Python 2.2.1,
-    type(iter(())): _iteratorChecker,  # different in Python 2.3.
+    type(iter([])): _iteratorChecker,
+    type(iter(())): _iteratorChecker,
     type(iter({})): _iteratorChecker,
     type(iter(set())): _iteratorChecker,
     type(iter(_Sequence())): _iteratorChecker,
@@ -903,8 +896,7 @@ _default_checkers = {
         _implied=CheckerPublic,
         subscribe=CheckerPublic,
         # To iterate, Python calls __len__ as a hint.
-        # Python 2 ignores AttributeErrors, but Python 3
-        # lets them pass.
+        # AttributeErrors are passed.
         __len__=CheckerPublic,
     ),
     zope.interface.interface.Method: InterfaceChecker(
@@ -915,13 +907,6 @@ _default_checkers = {
     zope.interface.declarations.Declaration: _Declaration_checker,
     abc.ABCMeta: _typeChecker,
 }
-if PYTHON2:  # pragma: no cover
-    _default_checkers[types.ClassType] = _typeChecker
-    _default_checkers[types.InstanceType] = _instanceChecker
-    # slot description
-    _default_checkers[type({}.iteritems())] = _iteratorChecker
-    _default_checkers[type({}.iterkeys())] = _iteratorChecker
-    _default_checkers[type({}.itervalues())] = _iteratorChecker
 
 
 def _fixup_dictlike(dict_type):
@@ -940,10 +925,6 @@ def _fixup_dictlike(dict_type):
 
 
 def _fixup_odict():
-    # OrderedDicts have three different implementations: Python 2 (pure
-    # python, returns generators and lists), Python <=3.4 (pure Python,
-    # 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
@@ -1008,12 +989,12 @@ def _fixup_zope_interface():
         pass
 
     @implementer(I1)
-    class Obj(object):
+    class Obj:
         pass
 
     o = Obj()
 
-    # This will be athe zope.interface.implementedBy from the class
+    # This will be the zope.interface.implementedBy from the class
     # a zope.interface.declarations.Implements
     _default_checkers[type(providedBy(o))] = NoProxy
 
@@ -1028,7 +1009,7 @@ del _fixup_zope_interface
 
 def _fixup_itertools():
     # itertools.groupby is a built-in custom iterator type introduced
-    # in python2.4. It should have the same checker as other built-in
+    # in Python 2.4. It should have the same checker as other built-in
     # iterators.
 
     # Also, itertools._grouper also needs to be exposed as an
@@ -1053,40 +1034,24 @@ def _fixup_itertools():
         return x
     iterable = (1, 2, 3)
     pred_iterable = (pred, iterable)
-    missing_in_py3 = {'ifilter', 'ifilterfalse', 'imap',
-                      'izip', 'izip_longest'}
-    missing_in_py2 = {'zip_longest', 'accumulate', 'compress',
-                      'combinations', 'combinations_with_replacement'}
-    missing = missing_in_py3 if sys.version_info[0] >= 3 else missing_in_py2
     for func, args in (
             ('count', ()),
             ('cycle', ((),)),
             ('dropwhile', pred_iterable),
-            ('ifilter', pred_iterable),
-            ('ifilterfalse', pred_iterable),
-            ('imap', pred_iterable),
             ('islice', (iterable, 2)),
-            ('izip', (iterable,)),
-            ('izip_longest', (iterable,)),
             ('permutations', (iterable,)),
             ('product', (iterable,)),
             ('repeat', (1, 2)),
             ('starmap', pred_iterable),
             ('takewhile', pred_iterable),
             ('tee', (iterable,)),
-            # Python 3 additions
             ('zip_longest', (iterable,)),
             ('accumulate', (iterable,)),
             ('compress', (iterable, ())),
             ('combinations', (iterable, 1)),
             ('combinations_with_replacement', (iterable, 1)),
     ):
-        try:
-            func = getattr(itertools, func)
-        except AttributeError:
-            assert func in missing, "Expected %s but not found" % (func,)
-            # The following line is hit on PY2, but it doesn't always show:
-            continue  # pragma: no cover
+        func = getattr(itertools, func)
 
         result = func(*args)
         if func == itertools.tee:
diff --git a/src/zope/security/decorator.py b/src/zope/security/decorator.py
index 18751d8..5ad9649 100644
--- a/src/zope/security/decorator.py
+++ b/src/zope/security/decorator.py
@@ -27,7 +27,7 @@ from zope.security.proxy import Proxy
 from zope.security.proxy import getChecker
 
 
-class DecoratedSecurityCheckerDescriptor(object):
+class DecoratedSecurityCheckerDescriptor:
     """Descriptor for a Decorator that provides a decorated security checker.
     """
 
@@ -36,7 +36,7 @@ class DecoratedSecurityCheckerDescriptor(object):
             return self
         else:
             proxied_object = getProxiedObject(inst)
-            if type(proxied_object) is Proxy:
+            if isinstance(proxied_object, Proxy):
                 checker = getChecker(proxied_object)
             else:
                 checker = getattr(proxied_object, '__Security_checker__', None)
diff --git a/src/zope/security/examples/sandbox.py b/src/zope/security/examples/sandbox.py
index 70dd5a8..b10d7b6 100644
--- a/src/zope/security/examples/sandbox.py
+++ b/src/zope/security/examples/sandbox.py
@@ -70,7 +70,7 @@ class SandboxError(Exception):
     pass
 
 
-class Identity(object):
+class Identity:
     """Mixin for pretty printing and identity method"""
 
     def __init__(self, id, *args, **kw):
@@ -80,7 +80,7 @@ class Identity(object):
         return self.id
 
     def __str__(self):
-        return "<%s> %s" % (str(self.__class__.__name__), str(self.id))
+        return "<{}> {}".format(str(self.__class__.__name__), str(self.id))
 
     __repr__ = __str__
 
@@ -165,13 +165,13 @@ class Sandbox(Identity):
             destination.addAgent(agent)
             del self._agents[agent.getId()]
         else:
-            raise SandboxError("couldn't transport agent %s to %s" % (
+            raise SandboxError("couldn't transport agent {} to {}".format(
                 agent, destination)
             )
 
 
 @implementer(IService)
-class Service(object):
+class Service:
     def getId(self):
         return self.__class__.__name__
 
@@ -231,7 +231,7 @@ def action_find_time(agent, home):
     return time_service.getTime()
 
 
-class TimeGenerator(object):
+class TimeGenerator:
     """Represents the passage of time in the agent simulation.
 
     each turn represents some discrete unit of time, during
@@ -283,7 +283,7 @@ class TimeGenerator(object):
 
 def WanderLust(agent):
     """ is agent ready to move """
-    if int(random.random()*100) <= 30:
+    if int(random.random() * 100) <= 30:
         return 1
 
 
diff --git a/src/zope/security/examples/sandbox_security.py b/src/zope/security/examples/sandbox_security.py
index d102c5f..3618f06 100644
--- a/src/zope/security/examples/sandbox_security.py
+++ b/src/zope/security/examples/sandbox_security.py
@@ -52,7 +52,7 @@ ALL = 'All'
 def NoSetAttr(name): return NotAllowed
 
 
-class SimulationSecurityDatabase(object):
+class SimulationSecurityDatabase:
     """Security Database
 
     In the database, locations are mapped to authentication tokens to
@@ -106,7 +106,7 @@ class SimulationSecurityPolicy(simplepolicies.ParanoidSecurityPolicy):
 
 
 @implementer(IParticipation)
-class AgentParticipation(object):
+class AgentParticipation:
     """Agent Participation during the Simulation.
 
     A very simple participation that is specific to the simulations.
diff --git a/src/zope/security/metaconfigure.py b/src/zope/security/metaconfigure.py
index b09c725..c4d3b90 100644
--- a/src/zope/security/metaconfigure.py
+++ b/src/zope/security/metaconfigure.py
@@ -46,7 +46,7 @@ class ProtectionDeclarationException(Exception):
     pass
 
 
-class ClassDirective(object):
+class ClassDirective:
 
     def __init__(self, _context, class_):
         self.__id = dottedName(class_)  # this would barf on a module, anyway
diff --git a/src/zope/security/metadirectives.py b/src/zope/security/metadirectives.py
index c7e82e2..34cee99 100644
--- a/src/zope/security/metadirectives.py
+++ b/src/zope/security/metadirectives.py
@@ -156,8 +156,8 @@ class IModule(Interface):
     """Group security declarations about a module"""
 
     module = GlobalObject(
-        title=u"Module",
-        description=u"Pointer to the module object.",
+        title="Module",
+        description="Pointer to the module object.",
         required=True)
 
 
@@ -170,16 +170,16 @@ class IAllow(Interface):
     """
 
     attributes = Tokens(
-        title=u"Attributes",
-        description=u"The attributes to provide access to.",
+        title="Attributes",
+        description="The attributes to provide access to.",
         value_type=PythonIdentifier(),
         required=False)
 
     interface = Tokens(
-        title=u"Interface",
-        description=(u"Interfaces whos names to provide access to. Access "
-                     u"will be provided to all of the names defined by the "
-                     u"interface(s). Multiple interfaces can be supplied."),
+        title="Interface",
+        description=("Interfaces whos names to provide access to. Access "
+                     "will be provided to all of the names defined by the "
+                     "interface(s). Multiple interfaces can be supplied."),
         value_type=GlobalInterface(),
         required=False)
 
@@ -193,11 +193,11 @@ class IRequire(Interface):
     """
 
     attributes = Tokens(
-        title=u"Attributes",
-        description=u"The attributes to require permission for.",
+        title="Attributes",
+        description="The attributes to require permission for.",
         value_type=PythonIdentifier(),
         required=False)
 
     permission = Permission(
-        title=u"Permission ID",
-        description=u"The ID of the permission to require.")
+        title="Permission ID",
+        description="The ID of the permission to require.")
diff --git a/src/zope/security/permission.py b/src/zope/security/permission.py
index 8fc2837..9103477 100644
--- a/src/zope/security/permission.py
+++ b/src/zope/security/permission.py
@@ -31,12 +31,12 @@ from zope.security.interfaces import IPermission
 
 
 @implementer(IPermission)
-class Permission(object):
+class Permission:
     """
     Default implementation of :class:`zope.security.interfaces.IPermission`.
     """
 
-    def __init__(self, id, title=u"", description=u""):
+    def __init__(self, id, title="", description=""):
         self.id = id
         self.title = title
         self.description = description
@@ -103,7 +103,7 @@ def PermissionIdsVocabulary(context=None):
             terms.append(SimpleTerm(name, name, name))
     terms = sorted(terms, key=operator.attrgetter('title'))
     if has_public:
-        terms.insert(0, SimpleTerm(CheckerPublic, zope_Public, u'Public'))
+        terms.insert(0, SimpleTerm(CheckerPublic, zope_Public, 'Public'))
     return SimpleVocabulary(terms)
 
 
diff --git a/src/zope/security/proxy.py b/src/zope/security/proxy.py
index 52a7189..c8db35a 100644
--- a/src/zope/security/proxy.py
+++ b/src/zope/security/proxy.py
@@ -21,7 +21,6 @@ import sys
 
 from zope.proxy import PyProxyBase
 
-from zope.security._compat import _BUILTINS
 from zope.security._compat import PURE_PYTHON
 
 
@@ -81,7 +80,7 @@ class ProxyPy(PyProxyBase):
     __slots__ = ('_wrapped', '_checker')
 
     def __new__(cls, value, checker):
-        inst = super(ProxyPy, cls).__new__(cls)
+        inst = super().__new__(cls)
         inst._wrapped = value
         inst._checker = checker
         return inst
@@ -98,10 +97,10 @@ class ProxyPy(PyProxyBase):
             # Only allow _wrapped and _checker to be accessed from inside.
             if sys._getframe(1).f_locals.get('self') is not self:
                 raise AttributeError(name)
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         if name == '_wrapped':
             return wrapped
-        checker = super(ProxyPy, self).__getattribute__('_checker')
+        checker = super().__getattribute__('_checker')
         if name == '_checker':
             return checker
         if name not in ('__cmp__', '__hash__', '__bool__', '__nonzero__',
@@ -131,7 +130,7 @@ class ProxyPy(PyProxyBase):
             # this one attribute.
             val = getattr(wrapped, name)
         else:
-            val = super(ProxyPy, self).__getattribute__(name)
+            val = super().__getattribute__(name)
         return checker.proxy(val)
 
     def __getattr__(self, name):
@@ -154,94 +153,71 @@ class ProxyPy(PyProxyBase):
         # but we're consistent. We would provide a better error
         # message or even subclass of AttributeError, but that's liable to
         # break (doc)tests.
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-        checker = super(ProxyPy, self).__getattribute__('_checker')
+        wrapped = super().__getattribute__('_wrapped')
+        checker = super().__getattribute__('_checker')
         checker.check_getattr(wrapped, name)
         raise AttributeError(name)
 
     def __setattr__(self, name, value):
         if name in ('_wrapped', '_checker'):
-            return super(ProxyPy, self).__setattr__(name, value)
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-        checker = super(ProxyPy, self).__getattribute__('_checker')
+            return super().__setattr__(name, value)
+        wrapped = super().__getattribute__('_wrapped')
+        checker = super().__getattribute__('_checker')
         checker.check_setattr(wrapped, name)
         setattr(wrapped, name, value)
 
     def __delattr__(self, name):
         if name in ('_wrapped', '_checker'):
             raise AttributeError()
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-        checker = super(ProxyPy, self).__getattribute__('_checker')
+        wrapped = super().__getattribute__('_wrapped')
+        checker = super().__getattribute__('_checker')
         checker.check_setattr(wrapped, name)
         delattr(wrapped, name)
 
-    @_check_name
-    def __getslice__(self, start, end):  # pragma: no cover PY2
-        wrapped = object.__getattribute__(self, '_wrapped')
-        try:
-            getslice = wrapped.__getslice__
-        except AttributeError:
-            return wrapped.__getitem__(slice(start, end))
-        return getslice(start, end)
-
-    @_check_name
-    def __setslice__(self, start, end, value):  # pragma: no cover PY2
-        wrapped = object.__getattribute__(self, '_wrapped')
-        try:
-            setslice = wrapped.__setslice__
-        except AttributeError:
-            return wrapped.__setitem__(slice(start, end), value)
-        return setslice(start, end, value)
-
-    def __cmp__(self, other):  # pragma: no cover PY2
-        # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-        return cmp(wrapped, other)  # noqa: F821 undefined name 'cmp'
-
     def __lt__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped < other
 
     def __le__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped <= other
 
     def __eq__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped == other
 
     def __ne__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped != other
 
     def __ge__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped >= other
 
     def __gt__(self, other):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return wrapped > other
 
     def __hash__(self):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return hash(wrapped)
 
     def __nonzero__(self):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         return bool(wrapped)
     __bool__ = __nonzero__
 
     def __length_hint__(self):
         # no check
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
+        wrapped = super().__getattribute__('_wrapped')
         try:
             hint = wrapped.__length_hint__
         except AttributeError:
@@ -249,13 +225,6 @@ class ProxyPy(PyProxyBase):
         else:
             return hint()
 
-    def __coerce__(self, other):  # pragma: no cover PY2
-        # For some reason _check_name does not work for coerce()
-        wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-        checker = super(ProxyPy, self).__getattribute__('_checker')
-        checker.check(wrapped, '__coerce__')
-        return super(ProxyPy, self).__coerce__(other)
-
     def __str__(self):
         try:
             return _check_name(PyProxyBase.__str__)(self)
@@ -266,8 +235,8 @@ class ProxyPy(PyProxyBase):
             raise
         except:  # noqa: E722 do not use bare 'except'
             # The C implementation catches all exceptions.
-            wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-            return '<security proxied %s.%s instance at %s>' % (
+            wrapped = super().__getattribute__('_wrapped')
+            return '<security proxied {}.{} instance at {}>'.format(
                 wrapped.__class__.__module__, wrapped.__class__.__name__,
                 _fmt_address(wrapped))
 
@@ -280,8 +249,8 @@ class ProxyPy(PyProxyBase):
         except TypeError:
             raise
         except:  # noqa: E722 do not use bare 'except'
-            wrapped = super(ProxyPy, self).__getattribute__('_wrapped')
-            return '<security proxied %s.%s instance at %s>' % (
+            wrapped = super().__getattribute__('_wrapped')
+            return '<security proxied {}.{} instance at {}>'.format(
                 wrapped.__class__.__module__, wrapped.__class__.__name__,
                 _fmt_address(wrapped))
 
@@ -292,15 +261,15 @@ for name in ['__call__',
              # '__unicode__', # Unchecked in C proxy
              '__reduce__',
              '__reduce_ex__',
-             # '__lt__',      # Unchecked in C proxy (rich coparison)
-             # '__le__',      # Unchecked in C proxy (rich coparison)
-             # '__eq__',      # Unchecked in C proxy (rich coparison)
-             # '__ne__',      # Unchecked in C proxy (rich coparison)
-             # '__ge__',      # Unchecked in C proxy (rich coparison)
-             # '__gt__',      # Unchecked in C proxy (rich coparison)
-             # '__nonzero__', # Unchecked in C proxy (rich coparison)
-             # '__bool__',    # Unchecked in C proxy (rich coparison)
-             # '__hash__',    # Unchecked in C proxy (rich coparison)
+             # '__lt__',      # Unchecked in C proxy (rich comparison)
+             # '__le__',      # Unchecked in C proxy (rich comparison)
+             # '__eq__',      # Unchecked in C proxy (rich comparison)
+             # '__ne__',      # Unchecked in C proxy (rich comparison)
+             # '__ge__',      # Unchecked in C proxy (rich comparison)
+             # '__gt__',      # Unchecked in C proxy (rich comparison)
+             # '__nonzero__', # Unchecked in C proxy (rich comparison)
+             # '__bool__',    # Unchecked in C proxy (rich comparison)
+             # '__hash__',    # Unchecked in C proxy (rich comparison)
              # '__cmp__',     # Unchecked in C proxy
              '__getitem__',
              '__setitem__',
@@ -380,7 +349,7 @@ def getCheckerPy(proxy):
     return super(ProxyPy, proxy).__getattribute__('_checker')
 
 
-_builtin_isinstance = sys.modules[_BUILTINS].isinstance
+_builtin_isinstance = sys.modules['builtins'].isinstance
 
 
 def getObjectPy(proxy):
diff --git a/src/zope/security/simplepolicies.py b/src/zope/security/simplepolicies.py
index feaa104..7035e07 100644
--- a/src/zope/security/simplepolicies.py
+++ b/src/zope/security/simplepolicies.py
@@ -29,7 +29,7 @@ from zope.security.interfaces import ISecurityPolicy
 
 @zope.interface.implementer(IInteraction)
 @zope.interface.provider(ISecurityPolicy)
-class ParanoidSecurityPolicy(object):
+class ParanoidSecurityPolicy:
     """
     Prohibit all access by any non-system principal, unless the item
     is :data:`public <zope.security.checker.CheckerPublic>`.
diff --git a/src/zope/security/testing.py b/src/zope/security/testing.py
index be551ce..f725912 100644
--- a/src/zope/security/testing.py
+++ b/src/zope/security/testing.py
@@ -17,30 +17,17 @@ Testing support code.
 This module provides some helper/stub objects for setting up interactions.
 """
 import contextlib
-import re
-
-from zope.testing import renormalizing
 
 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
 
 
-_str_prefix = 'b' if PY2 else 'u'
-
-rules = [
-    (re.compile(_str_prefix + "('.*?')"), r"\1"),
-    (re.compile(_str_prefix + '(".*?")'), r"\1"),
-]
-output_checker = renormalizing.RENormalizing(rules)
-
-
 @interface.implementer(interfaces.IPrincipal)
-class Principal(object):
+class Principal:
     """
     A trivial implementation of :class:`zope.security.interfaces.IPrincipal`.
     """
@@ -55,7 +42,7 @@ class Principal(object):
 
 
 @interface.implementer(interfaces.IParticipation)
-class Participation(object):
+class Participation:
     """
     A trivial implementation of
     :class:`zope.security.interfaces.IParticipation`.
diff --git a/src/zope/security/tests/__init__.py b/src/zope/security/tests/__init__.py
index e8db221..70e1049 100644
--- a/src/zope/security/tests/__init__.py
+++ b/src/zope/security/tests/__init__.py
@@ -1,7 +1,7 @@
 import io
 
 
-class QuietWatchingChecker(object):
+class QuietWatchingChecker:
     # zope.testrunner does not support setUp/tearDownModule,
     # so we use a mixin class to make sure we don't flood stderr
     # with pointless printing when testing watching checkers
diff --git a/src/zope/security/tests/exampleclass.py b/src/zope/security/tests/exampleclass.py
index 385dda0..9feab5a 100644
--- a/src/zope/security/tests/exampleclass.py
+++ b/src/zope/security/tests/exampleclass.py
@@ -16,7 +16,7 @@
 from zope.interface import Interface
 
 
-class ExampleClass(object):
+class ExampleClass:
     pass
 
 
diff --git a/src/zope/security/tests/test_adapter.py b/src/zope/security/tests/test_adapter.py
index 20a3975..6fd274c 100644
--- a/src/zope/security/tests/test_adapter.py
+++ b/src/zope/security/tests/test_adapter.py
@@ -30,7 +30,7 @@ class Test_assertLocation(unittest.TestCase):
         return assertLocation(adapter, parent)
 
     def test_w_non_ILocation(self):
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         parent = object()
@@ -41,7 +41,7 @@ class Test_assertLocation(unittest.TestCase):
 
     def test_w_ILocation_no_parent(self):
         @implementer(ILocation)
-        class _Adapter(object):
+        class _Adapter:
             __parent__ = None
         adapter = _Adapter()
         parent = object()
@@ -53,7 +53,7 @@ class Test_assertLocation(unittest.TestCase):
         parent = object()
 
         @implementer(ILocation)
-        class _Adapter(object):
+        class _Adapter:
             __parent__ = parent
         adapter = _Adapter()
         new_parent = object()
@@ -72,7 +72,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         return self._getTargetClass()(factory)
 
     def _makeFactory(self):
-        class _Factory(object):
+        class _Factory:
             __name__ = 'testing'
             __module__ = 'zope.security.tests.test_adapter'
             _called_with = ()
@@ -93,7 +93,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         before = factory.__dict__.copy()
@@ -108,7 +108,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         extra = object()
@@ -126,7 +126,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         returned = ltaf(adapter)
@@ -139,7 +139,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         returned = ltaf(adapter)
@@ -152,7 +152,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         proxy = ProxyFactory(adapter)
@@ -174,7 +174,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         extra = object()
@@ -197,10 +197,10 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
 
-        class _Extra(object):
+        class _Extra:
             pass
         adapter = _NotAdapter()
         extra = _Extra()
@@ -226,7 +226,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _Adapter(object):
+        class _Adapter:
             pass
         adapter = _Adapter()
         proxy = ProxyFactory(adapter)
@@ -254,7 +254,7 @@ class LocatingTrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _Adapter(object):
+        class _Adapter:
             pass
         adapter = _Adapter()
         proxy = ProxyFactory(adapter)
@@ -282,7 +282,7 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         return self._getTargetClass()(factory)
 
     def _makeFactory(self):
-        class _Factory(object):
+        class _Factory:
             __name__ = 'testing'
             __module__ = 'zope.security.tests.test_adapter'
 
@@ -297,7 +297,7 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         proxy = ProxyFactory(adapter)
@@ -318,7 +318,7 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         extra = object()
@@ -340,10 +340,10 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
 
-        class _Extra(object):
+        class _Extra:
             pass
         adapter = _NotAdapter()
         extra = _Extra()
@@ -367,7 +367,7 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _Adapter(object):
+        class _Adapter:
             pass
         adapter = _Adapter()
         proxy = ProxyFactory(adapter)
@@ -392,7 +392,7 @@ class TrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _Adapter(object):
+        class _Adapter:
             pass
         adapter = _Adapter()
         proxy = ProxyFactory(adapter)
@@ -419,7 +419,7 @@ class LocatingUntrustedAdapterFactoryTests(unittest.TestCase):
         return self._getTargetClass()(factory)
 
     def _makeFactory(self):
-        class _Factory(object):
+        class _Factory:
             __name__ = 'testing'
             __module__ = 'zope.security.tests.test_adapter'
             _called_with = ()
@@ -440,7 +440,7 @@ class LocatingUntrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         before = factory.__dict__.copy()
@@ -457,7 +457,7 @@ class LocatingUntrustedAdapterFactoryTests(unittest.TestCase):
         factory = self._makeFactory()
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         extra = object()
@@ -477,7 +477,7 @@ class LocatingUntrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         returned = ltaf(adapter)
@@ -490,7 +490,7 @@ class LocatingUntrustedAdapterFactoryTests(unittest.TestCase):
         directlyProvides(factory, ILocation)
         ltaf = self._makeOne(factory)
 
-        class _NotAdapter(object):
+        class _NotAdapter:
             pass
         adapter = _NotAdapter()
         returned = ltaf(adapter)
diff --git a/src/zope/security/tests/test_checker.py b/src/zope/security/tests/test_checker.py
index a102ad6..457ecd7 100644
--- a/src/zope/security/tests/test_checker.py
+++ b/src/zope/security/tests/test_checker.py
@@ -16,8 +16,6 @@
 import unittest
 
 from zope.security import checker as sec_checker
-from zope.security._compat import PYTHON2 as PY2
-from zope.security._compat import PYTHON3 as PY3
 from zope.security.tests import QuietWatchingChecker
 
 
@@ -86,7 +84,7 @@ class Test_ProxyFactory(unittest.TestCase):
         from zope.security.proxy import getObject
         _check = object()  # don't use a func, due to bound method
 
-        class _WithChecker(object):
+        class _WithChecker:
             __Security_checker__ = _check
         obj = _WithChecker()
         returned = self._callFUT(obj)
@@ -101,7 +99,7 @@ class Test_ProxyFactory(unittest.TestCase):
         from zope.security.proxy import getChecker
         from zope.security.proxy import getObject
 
-        class _Obj(object):
+        class _Obj:
             pass
         obj = _Obj()
         _checker = Checker({})
@@ -125,7 +123,7 @@ class Test_canWrite(unittest.TestCase):
         return canWrite(obj, name)
 
     def _makeChecker(self, ch_get=None, ch_set=None):
-        class _Checker(object):
+        class _Checker:
             def check_getattr(self, obj, name):
                 if ch_get is not None:
                     raise ch_get()
@@ -180,7 +178,7 @@ class Test_canAccess(unittest.TestCase):
         return canAccess(obj, name)
 
     def _makeChecker(self, ch_get=None):
-        class _Checker(object):
+        class _Checker:
             def check_getattr(self, obj, name):
                 if ch_get is not None:
                     raise ch_get()
@@ -284,7 +282,7 @@ class CheckerTestsBase(QuietWatchingChecker):
     def test_check_setattr_w_interaction_allows(self):
         from zope.security._definitions import thread_local
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return True
         checker = self._makeOne(set_permissions={'name': 'view'})
@@ -299,7 +297,7 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
         checker = self._makeOne(set_permissions={'name': 'view'})
@@ -332,7 +330,7 @@ class CheckerTestsBase(QuietWatchingChecker):
     def test_check_non_public_w_interaction_allows(self):
         from zope.security._definitions import thread_local
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return True
         checker = self._makeOne({'name': 'view'})
@@ -347,7 +345,7 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
         checker = self._makeOne({'name': 'view'})
@@ -383,7 +381,7 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security.proxy import getObject
         _check = object()  # don't use a func, due to bound method
 
-        class _WithChecker(object):
+        class _WithChecker:
             __Security_checker__ = _check
         obj = _WithChecker()
         checker = self._makeOne()
@@ -399,7 +397,7 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security.proxy import getChecker
         from zope.security.proxy import getObject
 
-        class _Obj(object):
+        class _Obj:
             pass
         obj = _Obj()
         _checker = Checker({})
@@ -448,8 +446,6 @@ class CheckerTestsBase(QuietWatchingChecker):
         self.assertEqual(proxy // Decimal('1'), Decimal('1'))
         self.assertEqual(float(proxy), 1.1)
         self.assertEqual(int(proxy), 1)
-        if PY2:  # pragma: no cover PY2
-            self.assertEqual(long(proxy), 1)  # noqa: F821 undefined name
         self.assertEqual(proxy ** 2, Decimal('1.21'))
         self.assertEqual(1 ** proxy, Decimal('1'))
         self.assertEqual(proxy.adjusted(), 0)
@@ -513,7 +509,7 @@ class CheckerTestsBase(QuietWatchingChecker):
             pass
 
         @implementer(I1)
-        class Obj(object):
+        class Obj:
             pass
 
         o = Obj()
@@ -546,7 +542,7 @@ class CheckerTestsBase(QuietWatchingChecker):
             pass
 
         @implementer(I1)
-        class Obj(object):
+        class Obj:
             pass
 
         o = Obj()
@@ -571,7 +567,7 @@ class CheckerTestsBase(QuietWatchingChecker):
         from zope.security.checker import _iteratorChecker
         from zope.security.proxy import Proxy
 
-        class Iter(object):
+        class Iter:
             __Security_checker__ = _iteratorChecker
 
             items = (0, 1, 2)
@@ -673,7 +669,6 @@ class TestTracebackSupplement(unittest.TestCase):
         return self._getTargetClass()(obj)
 
     def test_getInfo_builtin_types(self):
-        from zope.security._compat import _BUILTINS
         for val, typ in [('', 'str'),
                          (0, 'int'),
                          (1.0, 'float'),
@@ -683,12 +678,12 @@ class TestTracebackSupplement(unittest.TestCase):
                          ]:
             tbs = self._makeOne(val)
             self.assertEqual(tbs.getInfo().splitlines(),
-                             ['   - class: %s.%s' % (_BUILTINS, typ),
-                              '   - type: %s.%s' % (_BUILTINS, typ),
+                             ['   - class: builtins.{}'.format(typ),
+                              '   - type: builtins.{}'.format(typ),
                               ])
 
     def test_getInfo_newstyle_instance(self):
-        class C(object):
+        class C:
             pass
         tbs = self._makeOne(C())
         self.assertEqual(tbs.getInfo().splitlines(),
@@ -704,11 +699,8 @@ class TestTracebackSupplement(unittest.TestCase):
         lines = tbs.getInfo().splitlines()
         self.assertEqual(lines[0],
                          '   - class: %s.C' % self.__class__.__module__)
-        kind = ('__builtin__.instance'
-                if PY2
-                else '%s.C' % self.__class__.__module__)
         self.assertEqual(lines[1],
-                         '   - type: ' + kind)
+                         '   - type: %s.C' % self.__class__.__module__)
 
 
 class TestGlobal(unittest.TestCase):
@@ -940,7 +932,7 @@ class Test_MultiChecker(unittest.TestCase):
                           [(('foo', 'bar'), CheckerPublic), spec])
 
 
-class _SelectCheckerBase(object):
+class _SelectCheckerBase:
     # pylint:disable=no-member
 
     def _callFUT(self, obj):
@@ -963,7 +955,7 @@ class _SelectCheckerBase(object):
                     42,
                     3.14,
                     None,
-                    u'text',
+                    'text',
                     b'binary',
                     msg,
                     True,
@@ -979,7 +971,7 @@ class _SelectCheckerBase(object):
         from zope.security.checker import Checker
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = _checkers[Foo] = Checker({})
         self.assertIs(self._callFUT(Foo()), checker)
@@ -988,7 +980,7 @@ class _SelectCheckerBase(object):
         from zope.security.checker import Checker
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = Checker({})
 
@@ -1001,7 +993,7 @@ class _SelectCheckerBase(object):
         from zope.security.checker import NoProxy
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
 
         def _factory(obj):
@@ -1012,7 +1004,7 @@ class _SelectCheckerBase(object):
     def test_w_factory_returning_None(self):
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
 
         def _factory(obj):
@@ -1024,7 +1016,7 @@ class _SelectCheckerBase(object):
         from zope.security.checker import Checker
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = Checker({})
 
@@ -1045,40 +1037,24 @@ class _SelectCheckerBase(object):
             return x
         iterable = (1, 2, 3)
         pred_iterable = (pred, iterable)
-        missing_in_py3 = {'ifilter', 'ifilterfalse', 'imap',
-                          'izip', 'izip_longest'}
-        missing_in_py2 = {'zip_longest', 'accumulate', 'compress',
-                          'combinations', 'combinations_with_replacement'}
-        missing = missing_in_py3 if PY3 else missing_in_py2
         for func, args in (
                 ('count', ()),
                 ('cycle', ((),)),
                 ('dropwhile', pred_iterable),
-                ('ifilter', pred_iterable),
-                ('ifilterfalse', pred_iterable),
-                ('imap', pred_iterable),
                 ('islice', (iterable, 2)),
-                ('izip', (iterable,)),
-                ('izip_longest', (iterable,)),
                 ('permutations', (iterable,)),
                 ('product', (iterable,)),
                 ('repeat', (1, 2)),
                 ('starmap', pred_iterable),
                 ('takewhile', pred_iterable),
                 ('tee', (iterable,)),
-                # Python 3 additions
                 ('zip_longest', (iterable,)),
                 ('accumulate', (iterable,)),
                 ('compress', (iterable, ())),
                 ('combinations', (iterable, 1)),
                 ('combinations_with_replacement', (iterable, 1)),
         ):
-            try:
-                func = getattr(itertools, func)
-            except AttributeError:
-                if func in missing:
-                    continue
-                self.fail("Attribute error raised", func)
+            func = getattr(itertools, func)
             __traceback_info__ = func
             result = func(*args)
             if func == itertools.tee:
@@ -1118,14 +1094,14 @@ class Test_getCheckerForInstancesOf(unittest.TestCase):
         return getCheckerForInstancesOf(obj)
 
     def test_miss(self):
-        class Unknown(object):
+        class Unknown:
             pass
         self.assertIsNone(self._callFUT(Unknown))
 
     def test_hit(self):
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = _checkers[Foo] = object()
         self.assertIs(self._callFUT(Foo), checker)
@@ -1151,7 +1127,7 @@ class Test_defineChecker(unittest.TestCase):
                     42,
                     3.14,
                     None,
-                    u'text',
+                    'text',
                     b'binary',
                     True,
                     ]:
@@ -1162,7 +1138,7 @@ class Test_defineChecker(unittest.TestCase):
 
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker1, checker2 = object(), object()
         _checkers[Foo] = checker1
@@ -1172,7 +1148,7 @@ class Test_defineChecker(unittest.TestCase):
         from zope.security.checker import _checkers
         checker = object()
 
-        class Foo(object):
+        class Foo:
             pass
         self._callFUT(Foo, checker)
         self.assertIs(_checkers[Foo], checker)
@@ -1210,14 +1186,14 @@ class Test_undefineChecker(unittest.TestCase):
         return undefineChecker(type_)
 
     def test_miss(self):
-        class Foo(object):
+        class Foo:
             pass
         self.assertRaises(KeyError, self._callFUT, Foo)
 
     def test_hit(self):
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         _checkers[Foo] = object()
         self._callFUT(Foo)
@@ -1275,7 +1251,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.checker import CheckerPublic
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1292,7 +1268,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1310,7 +1286,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1345,7 +1321,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1376,7 +1352,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.checker import CheckerPublic
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1393,7 +1369,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1411,7 +1387,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1446,7 +1422,7 @@ class TestCombinedChecker(QuietWatchingChecker,
         from zope.security._definitions import thread_local
         from zope.security.interfaces import Unauthorized
 
-        class _Interaction(object):
+        class _Interaction:
             def checkPermission(self, obj, perm):
                 return False
 
@@ -1477,7 +1453,7 @@ class TestCheckerLoggingMixin(unittest.TestCase):
         return CheckerLoggingMixin
 
     def _makeOne(self, raising=None):
-        class _Checker(object):
+        class _Checker:
             def __init__(self, raising, stream):
                 self._file = stream
                 self._raising = raising
@@ -1498,7 +1474,7 @@ class TestCheckerLoggingMixin(unittest.TestCase):
         return _Stream()
 
     def _makeObject(self):
-        class _Object(object):
+        class _Object:
             def __repr__(self):
                 return 'TESTING'
         return _Object()
@@ -1653,14 +1629,14 @@ class Test__instanceChecker(unittest.TestCase):
     def test_miss(self):
         from zope.security.checker import _defaultChecker
 
-        class Foo(object):
+        class Foo:
             pass
         self.assertIs(self._callFUT(Foo()), _defaultChecker)
 
     def test_hit(self):
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = _checkers[Foo] = object()
         self.assertIs(self._callFUT(Foo()), checker)
@@ -1698,7 +1674,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
                          unittest.TestCase):
 
     def setUp(self):
-        super(TestSecurityPolicy, self).setUp()
+        super().setUp()
 
         from zope.security.management import newInteraction
         from zope.security.management import setSecurityPolicy
@@ -1707,7 +1683,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         newInteraction()
 
     def tearDown(self):
-        super(TestSecurityPolicy, self).tearDown()
+        super().tearDown()
 
         from zope.security.management import endInteraction
         from zope.security.management import setSecurityPolicy
@@ -1719,8 +1695,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         # Py3 has no ClassType and no old-style classes
         import types
         old_type = getattr(types, 'ClassType', type)
-        self.assertTrue((PY2 and old_type is not type)
-                        or (PY3 and old_type is type))
+        self.assertTrue(old_type is type)
         return old_type
 
     def _makeSecurityPolicy(self):
@@ -1729,27 +1704,16 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.interfaces import ISecurityPolicy
 
         @implementer(ISecurityPolicy)
-        class SecurityPolicy(object):
+        class SecurityPolicy:
             def checkPermission(self, permission, _object):
                 return permission == 'test_allowed'
         return SecurityPolicy
 
-    def test_defineChecker_oldstyle_class(self):
-        from zope.security.checker import NamesChecker
-        from zope.security.checker import defineChecker
-        old_type = self._get_old_class_type()
-
-        class ClassicClass:
-            __metaclass__ = old_type
-        self.assertIsInstance(ClassicClass, old_type)
-
-        defineChecker(ClassicClass, NamesChecker())
-
-    def test_defineChecker_newstyle_class(self):
+    def test_defineChecker_class(self):
         from zope.security.checker import NamesChecker
         from zope.security.checker import defineChecker
 
-        class NewStyleClass(object):
+        class NewStyleClass:
             pass
         self.assertIsInstance(NewStyleClass, type)
         defineChecker(NewStyleClass, NamesChecker())
@@ -1789,7 +1753,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
 
         self.assertIsInstance(OldInst, old_type)
 
-        class NewInst(OldInst, object):
+        class NewInst(OldInst):
             # This is not needed, but left in to show the change of metaclass
             # __metaclass__ = type
             def gete(self):
@@ -2018,7 +1982,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.checker import NamesChecker
         checker = NamesChecker(())
 
-        class C(object):
+        class C:
             pass
         self.assertEqual(checker.check(C, '__hash__'), None)
         self.assertEqual(checker.check(C, '__nonzero__'), None)
@@ -2059,7 +2023,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.proxy import Proxy
         from zope.security.proxy import getChecker
 
-        class SomeClass(object):
+        class SomeClass:
             pass
         checker = NamesChecker()
         specific_checker = NamesChecker()
@@ -2092,7 +2056,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.checker import defineChecker
         from zope.security.checker import undefineChecker
 
-        class SomeClass(object):
+        class SomeClass:
             pass
         obj = SomeClass()
 
@@ -2109,7 +2073,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.checker import NamesChecker
         from zope.security.checker import ProxyFactory
 
-        class SomeClass(object):
+        class SomeClass:
             pass
         obj = SomeClass()
         checker = NamesChecker()
@@ -2143,7 +2107,7 @@ class TestSecurityPolicy(QuietWatchingChecker,
         from zope.security.checker import defineChecker
         from zope.security.interfaces import Forbidden
 
-        class SomeClass(object):
+        class SomeClass:
             pass
         obj = SomeClass()
 
@@ -2257,7 +2221,7 @@ class TestMixinDecoratedChecker(unittest.TestCase):
         from zope.security.interfaces import ISecurityPolicy
 
         @implementer(ISecurityPolicy)
-        class RecordedSecurityPolicy(object):
+        class RecordedSecurityPolicy:
             def __init__(self):
                 self._checked = []
                 self.permissions = {}
@@ -2319,12 +2283,12 @@ class TestCombinedCheckerMixin(QuietWatchingChecker,
                                unittest.TestCase):
 
     def setUp(self):
-        super(TestCombinedCheckerMixin, self).setUp()
+        super().setUp()
         self.decoratedSetUp()
 
     def tearDown(self):
         self.decoratedTearDown()
-        super(TestCombinedCheckerMixin, self).tearDown()
+        super().tearDown()
 
     def test_checking(self):
         from zope.security.checker import CombinedChecker
@@ -2370,7 +2334,7 @@ class TestBasicTypes(unittest.TestCase):
         from zope.security.checker import BasicTypes
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = object()
         BasicTypes[Foo] = checker
@@ -2381,7 +2345,7 @@ class TestBasicTypes(unittest.TestCase):
         from zope.security.checker import BasicTypes
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = object()
         BasicTypes[Foo] = checker
@@ -2397,10 +2361,10 @@ class TestBasicTypes(unittest.TestCase):
         from zope.security.checker import BasicTypes
         from zope.security.checker import _checkers
 
-        class Foo(object):
+        class Foo:
             pass
         checker = object()
-        BasicTypes.update({Foo:  checker})
+        BasicTypes.update({Foo: checker})
         self.assertIs(BasicTypes[Foo], checker)
         self.assertIs(_checkers[Foo], checker)
 
@@ -2410,10 +2374,10 @@ class TestBasicTypes(unittest.TestCase):
         from zope.security.checker import _checkers
         from zope.security.checker import _clear
 
-        class MyType(object):
+        class MyType:
             pass
 
-        class MyType2(object):
+        class MyType2:
             pass
 
         # When an item is added to the basic types, it should also be added to
@@ -2450,12 +2414,6 @@ class TestBasicTypes(unittest.TestCase):
         self.assertIn(int, keys)
         self.assertIn(float, keys)
         self.assertIn(str, keys)
-        try:
-            unicode
-        except NameError:
-            pass
-        else:  # pragma: no cover PY2
-            self.assertIn(unicode, keys)  # noqa: F821 undefined name 'unicode'
         self.assertIn(object, keys)
         # ...
 
diff --git a/src/zope/security/tests/test_decorator.py b/src/zope/security/tests/test_decorator.py
index 756177a..c56a996 100644
--- a/src/zope/security/tests/test_decorator.py
+++ b/src/zope/security/tests/test_decorator.py
@@ -22,12 +22,12 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
                                               unittest.TestCase):
 
     def setUp(self):
-        super(DecoratedSecurityCheckerDescriptorTests, self).setUp()
+        super().setUp()
         from zope.security.checker import _clear
         _clear()
 
     def tearDown(self):
-        super(DecoratedSecurityCheckerDescriptorTests, self).tearDown()
+        super().tearDown()
         from zope.security.checker import _clear
         _clear()
 
@@ -44,7 +44,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         defineChecker(Foo, NoProxy)
         foo = Foo()
@@ -65,7 +65,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import defineChecker
         from zope.security.interfaces import ForbiddenAttribute
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         fooChecker = NamesChecker(['a'])  # a is public
         defineChecker(Foo, fooChecker)
@@ -96,7 +96,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         foo = Foo()
         defineChecker(Foo, NoProxy)
@@ -116,7 +116,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         fooChecker = NamesChecker(['a'])  # a is public
         defineChecker(Foo, fooChecker)
@@ -137,7 +137,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import defineChecker
         from zope.security.proxy import ProxyFactory
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         fooChecker = NamesChecker(['a'])  # a is public
         defineChecker(Foo, fooChecker)
@@ -162,7 +162,7 @@ class DecoratedSecurityCheckerDescriptorTests(QuietWatchingChecker,
         from zope.security.checker import NoProxy
         from zope.security.checker import defineChecker
 
-        class Foo(object):
+        class Foo:
             a = 'a'
         defineChecker(Foo, NoProxy)
         foo = Foo()
diff --git a/src/zope/security/tests/test_location.py b/src/zope/security/tests/test_location.py
index a620605..5de73a5 100644
--- a/src/zope/security/tests/test_location.py
+++ b/src/zope/security/tests/test_location.py
@@ -28,7 +28,7 @@ class LocationSecurityProxyTests(QuietWatchingChecker,
         from zope.security.checker import defineChecker
         from zope.security.proxy import ProxyFactory
 
-        class Unlocated(object):
+        class Unlocated:
             a = 'a'
         unlocated = Unlocated()
         located = LocationProxy(unlocated)
diff --git a/src/zope/security/tests/test_management.py b/src/zope/security/tests/test_management.py
index 6fb62cf7..7cc7e3b 100644
--- a/src/zope/security/tests/test_management.py
+++ b/src/zope/security/tests/test_management.py
@@ -141,7 +141,7 @@ class Test(unittest.TestCase):
         permission = 'zope.Test'
         obj = object()
 
-        class PolicyStub(object):
+        class PolicyStub:
             def checkPermission(s, p, o,):
                 self.assertTrue(p is permission)
                 self.assertTrue(o is obj)
@@ -161,7 +161,7 @@ class Test(unittest.TestCase):
 
         obj = object()
 
-        class ForbiddenPolicyStub(object):
+        class ForbiddenPolicyStub:
             def checkPermission(s, p, o):
                 return False
 
@@ -179,13 +179,13 @@ class Test(unittest.TestCase):
         from zope.security.management import system_user
 
         self.assertEqual(system_user.id,
-                         u'zope.security.management.system_user')
+                         'zope.security.management.system_user')
 
-        self.assertEqual(system_user.title, u'System')
+        self.assertEqual(system_user.title, 'System')
 
         for name in 'id', 'title', 'description':
             self.assertIsInstance(getattr(system_user, name),
-                                  type(u''))
+                                  str)
 
         verifyObject(IPrincipal, system_user)
         verifyObject(ISystemPrincipal, system_user)
diff --git a/src/zope/security/tests/test_metaconfigure.py b/src/zope/security/tests/test_metaconfigure.py
index a446b72..76471bd 100644
--- a/src/zope/security/tests/test_metaconfigure.py
+++ b/src/zope/security/tests/test_metaconfigure.py
@@ -104,7 +104,7 @@ class ClassDirectiveTests(unittest.TestCase):
     def test_require_only_like_class(self):
         from zope.security.protectclass import protectLikeUnto
 
-        class Bar(object):
+        class Bar:
             pass
         context = DummyZCMLContext()
         directive = self._makeOne(context, Foo)
@@ -230,8 +230,8 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.security.protectclass import protectSetAttribute
 
         class IFoo(Interface):
-            bar = Field(u"Bar")
-            baz = Field(u"Baz")
+            bar = Field("Bar")
+            baz = Field("Baz")
         context = DummyZCMLContext()
         directive = self._makeOne(context, Foo)
         directive.require(context, permission='testing', set_schema=[IFoo])
@@ -271,7 +271,7 @@ class ClassDirectiveTests(unittest.TestCase):
         from zope.schema import Field
 
         class IFoo(Interface):
-            bar = Field(u"Bar", readonly=True)
+            bar = Field("Bar", readonly=True)
         context = DummyZCMLContext()
         directive = self._makeOne(context, Foo)
         directive.require(context, permission='testing', set_schema=[IFoo])
@@ -423,7 +423,7 @@ class ClassDirectiveTests(unittest.TestCase):
         self.assertEqual(context._actions[1]['args'], ('', IFactory))
 
 
-class Foo(object):
+class Foo:
     pass
 
 
@@ -662,7 +662,7 @@ class Test_requre(unittest.TestCase):
                          ('testing', 'baz', perm))
 
 
-class DummyZCMLContext(object):
+class DummyZCMLContext:
 
     def __init__(self):
         self._actions = []
diff --git a/src/zope/security/tests/test_permission.py b/src/zope/security/tests/test_permission.py
index 075aed0..2326f37 100644
--- a/src/zope/security/tests/test_permission.py
+++ b/src/zope/security/tests/test_permission.py
@@ -48,15 +48,15 @@ class PermissionTests(unittest.TestCase):
 
     def test_ctor_only_id(self):
         permission = self._makeOne('testing')
-        self.assertEqual(permission.id, u'testing')
-        self.assertEqual(permission.title, u'')
-        self.assertEqual(permission.description, u'')
+        self.assertEqual(permission.id, 'testing')
+        self.assertEqual(permission.title, '')
+        self.assertEqual(permission.description, '')
 
     def test_ctor_w_title_and_description(self):
-        permission = self._makeOne('testing', u'TITLE', u'DESCRIPTION')
+        permission = self._makeOne('testing', 'TITLE', 'DESCRIPTION')
         self.assertEqual(permission.id, 'testing')
-        self.assertEqual(permission.title, u'TITLE')
-        self.assertEqual(permission.description, u'DESCRIPTION')
+        self.assertEqual(permission.title, 'TITLE')
+        self.assertEqual(permission.description, 'DESCRIPTION')
 
 
 class Test_checkPermission(PlacelessSetup, unittest.TestCase):
diff --git a/src/zope/security/tests/test_protectclass.py b/src/zope/security/tests/test_protectclass.py
index c1cdc09..4cbd95c 100644
--- a/src/zope/security/tests/test_protectclass.py
+++ b/src/zope/security/tests/test_protectclass.py
@@ -132,7 +132,7 @@ class Test_protectLikeUnto(unittest.TestCase):
                          foo_checker.set_permissions)
 
 
-class Foo(object):
+class Foo:
     bar = 'Bar'
 
 
diff --git a/src/zope/security/tests/test_proxy.py b/src/zope/security/tests/test_proxy.py
index 3570cad..68f370a 100644
--- a/src/zope/security/tests/test_proxy.py
+++ b/src/zope/security/tests/test_proxy.py
@@ -16,39 +16,14 @@
 import unittest
 
 from zope.security._compat import PURE_PYTHON
-from zope.security._compat import PYTHON2
 
 
-def _skip_if_not_Py2(testfunc):
-    return unittest.skipUnless(PYTHON2, "Only on Py2")(testfunc)
-
 # pylint:disable=protected-access,eval-used,too-many-lines,too-many-public-methods
 
-
-if not PYTHON2:  # pragma: PY3
-    def coerce(*args):
-        raise NotImplementedError("Not on Python 3")
-    cmp = coerce
-    long = int
-    unicode = str
-
-
-class AbstractProxyTestBase(object):
+class AbstractProxyTestBase:
 
     # pylint:disable=no-member,blacklisted-name
 
-    assertRaisesRegex = getattr(unittest.TestCase, 'assertRaisesRegex',
-                                unittest.TestCase.assertRaisesRegexp)
-
-    # The names of attributes that are spelled different on Py2
-    # vs Py3
-    itruediv = '__itruediv__' if not PYTHON2 else '__idiv__'
-    idiv = itruediv
-    div = '__truediv__' if not PYTHON2 else '__div__'
-    truediv = div
-    getslice = '__getitem__' if not PYTHON2 else '__getslice__'
-    setslice = '__setitem__' if not PYTHON2 else '__setslice__'
-
     def _getTargetClass(self):
         raise NotImplementedError("Subclass responsibility")
 
@@ -59,7 +34,7 @@ class AbstractProxyTestBase(object):
         self.assertRaises(ValueError, self._makeOne, object(), None)
 
     def test___getattr___w_checker_ok(self):
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker()
@@ -72,7 +47,7 @@ class AbstractProxyTestBase(object):
     def test___getattr___w_checker_unauthorized(self):
         from zope.security.interfaces import Unauthorized
 
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker(Unauthorized)
@@ -83,7 +58,7 @@ class AbstractProxyTestBase(object):
     def test___getattr___w_checker_forbidden_attribute(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker(ForbiddenAttribute)
@@ -94,7 +69,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, 'bar')
 
     def test__getattr__w_checker_ok_dynamic_attribute_called_once(self):
-        class Dynamic(object):
+        class Dynamic:
             count = 0
 
             def __getattr__(self, name):
@@ -113,7 +88,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(1, target.count)
 
     def test___setattr___w_checker_ok(self):
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker()
@@ -126,7 +101,7 @@ class AbstractProxyTestBase(object):
     def test___setattr___w_checker_unauthorized(self):
         from zope.security.interfaces import Unauthorized
 
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker(Unauthorized)
@@ -137,7 +112,7 @@ class AbstractProxyTestBase(object):
     def test___setattr___w_checker_forbidden_attribute(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class Foo(object):
+        class Foo:
             bar = 'Bar'
         target = Foo()
         checker = DummyChecker(ForbiddenAttribute)
@@ -146,7 +121,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, 'bar')
 
     def test___delattr___w_checker_ok(self):
-        class Foo(object):
+        class Foo:
             bar = None
         target = Foo()
         target.bar = 'Bar'
@@ -160,7 +135,7 @@ class AbstractProxyTestBase(object):
     def test___delattr___w_checker_unauthorized(self):
         from zope.security.interfaces import Unauthorized
 
-        class Foo(object):
+        class Foo:
             def __init__(self):
                 self.bar = 'Bar'
         target = Foo()
@@ -173,7 +148,7 @@ class AbstractProxyTestBase(object):
     def test___delattr___w_checker_forbidden_attribute(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class Foo(object):
+        class Foo:
             def __init__(self):
                 self.bar = 'Bar'
         target = Foo()
@@ -190,7 +165,6 @@ class AbstractProxyTestBase(object):
         self.assertEqual(str(proxy), str(target))
 
     def test___str___checker_forbids_str(self):
-        from zope.security._compat import _BUILTINS
         from zope.security.interfaces import ForbiddenAttribute
         from zope.security.proxy import _fmt_address
         target = object()
@@ -198,13 +172,13 @@ class AbstractProxyTestBase(object):
         proxy = self._makeOne(target, checker)
         address = _fmt_address(target)
         self.assertEqual(str(proxy),
-                         '<security proxied %s.object '
-                         'instance at %s>' % (_BUILTINS, address))
+                         '<security proxied builtins.object '
+                         'instance at %s>' % address)
 
     def test___str___fails_return(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class CustomStr(object):
+        class CustomStr:
             def __str__(self):
                 "<CustomStr>"  # Docstring, not a return
 
@@ -223,7 +197,6 @@ class AbstractProxyTestBase(object):
         self.assertEqual(repr(proxy), repr(target))
 
     def test___repr___checker_forbids_str(self):
-        from zope.security._compat import _BUILTINS
         from zope.security.interfaces import ForbiddenAttribute
         from zope.security.proxy import _fmt_address
         target = object()
@@ -231,13 +204,13 @@ class AbstractProxyTestBase(object):
         proxy = self._makeOne(target, checker)
         address = _fmt_address(target)
         self.assertEqual(repr(proxy),
-                         '<security proxied %s.object '
-                         'instance at %s>' % (_BUILTINS, address))
+                         '<security proxied builtins.object '
+                         'instance at %s>' % address)
 
     def test___str___falls_through_to_repr_when_both_allowed(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class CustomRepr(object):
+        class CustomRepr:
             def __repr__(self):
                 return "<CustomRepr>"
 
@@ -252,7 +225,7 @@ class AbstractProxyTestBase(object):
     def test___str___doesnot_fall_through_to_repr_when_str_not_allowed(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class CustomRepr(object):
+        class CustomRepr:
             def __repr__(self):
                 return "<CustomRepr>"
 
@@ -266,7 +239,7 @@ class AbstractProxyTestBase(object):
     def test___str___doesnot_fall_through_to_repr_when_repr_not_allowed(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class CustomRepr(object):
+        class CustomRepr:
             def __repr__(self):
                 return "<CustomRepr>"
 
@@ -280,7 +253,7 @@ class AbstractProxyTestBase(object):
     def test___str___falls_through_to_repr_but_repr_fails_return(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class CustomRepr(object):
+        class CustomRepr:
             def __repr__(self):
                 "<CustomRepr>"  # Docstring, not a return
 
@@ -292,36 +265,6 @@ class AbstractProxyTestBase(object):
         with self.assertRaises(TypeError):
             repr(proxy)
 
-    @_skip_if_not_Py2
-    def test___cmp___w_self(self):  # pragma: no cover
-        target = object()
-        checker = object()  # checker not consulted
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(cmp(proxy, proxy), 0)
-
-    @_skip_if_not_Py2
-    def test___cmp___w_target(self):  # pragma: no cover
-        target = object()
-        checker = object()  # checker not consulted
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(cmp(proxy, target), 0)
-
-    @_skip_if_not_Py2
-    def test___cmp___w_other(self):  # pragma: no cover
-        target = object()
-        other = object()
-        checker = object()  # checker not consulted
-        proxy = self._makeOne(target, checker)
-        self.assertNotEqual(cmp(proxy, other), 0)
-
-    @_skip_if_not_Py2
-    def test___cmp___w_other_proxy(self):  # pragma: no cover
-        target = object()
-        checker = object()  # checker not consulted
-        proxy = self._makeOne(target, checker)
-        o_proxy = self._makeOne(target, checker)
-        self.assertEqual(cmp(proxy, o_proxy), 0)
-
     def test__le__(self):
         target = 1
         checker = object()  # checker not consulted
@@ -353,7 +296,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(hash(proxy), hash(target))
 
     def test___call___w_checker_ok(self):
-        class Foo(object):
+        class Foo:
             def __call__(self):
                 return 'Bar'
         target = Foo()
@@ -366,7 +309,7 @@ class AbstractProxyTestBase(object):
     def test___call___w_checker_unauthorized(self):
         from zope.security.interfaces import Unauthorized
 
-        class Foo(object):
+        class Foo:
             def __call__(self):
                 raise AssertionError("Never called")
         target = Foo()
@@ -378,7 +321,7 @@ class AbstractProxyTestBase(object):
     def test___call___w_checker_forbidden_attribute(self):
         from zope.security.interfaces import ForbiddenAttribute
 
-        class Foo(object):
+        class Foo:
             def __call__(self):
                 raise AssertionError("Never called")
         target = Foo()
@@ -417,57 +360,6 @@ class AbstractProxyTestBase(object):
         self.assertRaises(ForbiddenAttribute, float, proxy)
         self.assertEqual(checker._checked, '__float__')
 
-    @_skip_if_not_Py2
-    def test___long___w_checker_allows(self):  # pragma: no cover
-        target = 3.0
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(long(proxy), long(target))
-        self.assertEqual(checker._checked, '__long__')
-
-    @_skip_if_not_Py2
-    def test___long___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = 3
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertRaises(ForbiddenAttribute, long, proxy)
-        self.assertEqual(checker._checked, '__long__')
-
-    @_skip_if_not_Py2
-    def test___oct___w_checker_allows(self):  # pragma: no cover
-        target = 3
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(oct(proxy), oct(target))
-        self.assertEqual(checker._checked, '__oct__')
-
-    @_skip_if_not_Py2
-    def test___oct___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = 3
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertRaises(ForbiddenAttribute, oct, proxy)
-        self.assertEqual(checker._checked, '__oct__')
-
-    @_skip_if_not_Py2
-    def test___hex___w_checker_allows(self):  # pragma: no cover
-        target = 3
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(hex(proxy), hex(target))
-        self.assertEqual(checker._checked, '__hex__')
-
-    @_skip_if_not_Py2
-    def test___hex___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = 3
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertRaises(ForbiddenAttribute, hex, proxy)
-        self.assertEqual(checker._checked, '__hex__')
-
     def test___add___w_checker_allows(self):
         target = 3
         checker = DummyChecker()
@@ -518,7 +410,7 @@ class AbstractProxyTestBase(object):
         checker = DummyChecker()
         proxy = self._makeOne(target, checker)
         self.assertEqual(proxy / 2, target / 2)
-        self.assertEqual(checker._checked, self.div)
+        self.assertEqual(checker._checked, '__truediv__')
 
     def test___div___w_checker_forbids(self):
         from zope.security.interfaces import ForbiddenAttribute
@@ -526,14 +418,14 @@ class AbstractProxyTestBase(object):
         checker = DummyChecker(ForbiddenAttribute)
         proxy = self._makeOne(target, checker)
         self.assertRaises(ForbiddenAttribute, lambda: proxy / 2)
-        self.assertEqual(checker._checked, self.div)
+        self.assertEqual(checker._checked, '__truediv__')
 
     def test___truediv___w_checker_allows(self):
         target = 3.0
         checker = DummyChecker()
         proxy = self._makeOne(target, checker)
         self.assertEqual(proxy / 2, target / 2)
-        self.assertEqual(checker._checked, self.truediv)
+        self.assertEqual(checker._checked, '__truediv__')
 
     def test___truediv___w_checker_forbids(self):
         from zope.security.interfaces import ForbiddenAttribute
@@ -541,7 +433,7 @@ class AbstractProxyTestBase(object):
         checker = DummyChecker(ForbiddenAttribute)
         proxy = self._makeOne(target, checker)
         self.assertRaises(ForbiddenAttribute, lambda: proxy / 2)
-        self.assertEqual(checker._checked, self.truediv)
+        self.assertEqual(checker._checked, '__truediv__')
 
     def test___floordiv___w_checker_allows(self):
         target = 3
@@ -759,23 +651,6 @@ class AbstractProxyTestBase(object):
         self.assertRaises(ForbiddenAttribute, lambda: proxy | 2)
         self.assertEqual(checker._checked, '__or__')
 
-    @_skip_if_not_Py2
-    def test___coerce___w_checker_allows(self):  # pragma: no cover
-        target = 3
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(coerce(proxy, 4.0), coerce(target, 4.0))
-        self.assertEqual(checker._checked, '__coerce__')
-
-    @_skip_if_not_Py2
-    def test___coerce___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = 3
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertRaises(ForbiddenAttribute, coerce, proxy, 4.0)
-        self.assertEqual(checker._checked, '__coerce__')
-
     def test___iadd___not_inplace_checker_allows(self):
         target = 3
         checker = DummyChecker()
@@ -786,7 +661,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__iadd__')
 
     def test___iadd___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -820,7 +695,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__isub__')
 
     def test___isub___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -854,7 +729,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__imul__')
 
     def test___imul___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -885,10 +760,10 @@ class AbstractProxyTestBase(object):
         proxy /= 3
         self.assertIsNot(proxy, before)
         self.assertEqual(proxy, 2)
-        self.assertEqual(checker._checked, self.idiv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___idiv___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -902,7 +777,7 @@ class AbstractProxyTestBase(object):
         proxy /= 3
         self.assertIs(proxy, before)
         self.assertEqual(target.value, 2)
-        self.assertEqual(checker._checked, self.idiv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___idiv___w_checker_forbids(self):
         from zope.security.interfaces import ForbiddenAttribute
@@ -911,7 +786,7 @@ class AbstractProxyTestBase(object):
         proxy = self._makeOne(target, checker)
         with self.assertRaises(ForbiddenAttribute):
             proxy /= 3
-        self.assertEqual(checker._checked, self.idiv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___itruediv___not_inplace_checker_allows(self):
         target = 6
@@ -920,10 +795,10 @@ class AbstractProxyTestBase(object):
         proxy /= 3
         self.assertIsNot(proxy, before)
         self.assertEqual(proxy, 2)
-        self.assertEqual(checker._checked, self.itruediv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___itruediv___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -937,7 +812,7 @@ class AbstractProxyTestBase(object):
         proxy /= 3
         self.assertIs(proxy, before)
         self.assertEqual(target.value, 2)
-        self.assertEqual(checker._checked, self.itruediv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___itruediv___w_checker_forbids(self):
         from zope.security.interfaces import ForbiddenAttribute
@@ -946,7 +821,7 @@ class AbstractProxyTestBase(object):
         proxy = self._makeOne(target, checker)
         with self.assertRaises(ForbiddenAttribute):
             proxy /= 3
-        self.assertEqual(checker._checked, self.itruediv)
+        self.assertEqual(checker._checked, '__itruediv__')
 
     def test___ifloordiv___not_inplace_checker_allows(self):
         target = 6
@@ -958,7 +833,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__ifloordiv__')
 
     def test___ifloordiv___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -992,7 +867,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__imod__')
 
     def test___imod___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1026,7 +901,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__ipow__')
 
     def test___ipow___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1060,7 +935,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__ilshift__')
 
     def test___ilshift___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1094,7 +969,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__irshift__')
 
     def test___irshift___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1128,7 +1003,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__iand__')
 
     def test___iand___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1162,7 +1037,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(proxy, 4)
 
     def test___ixor___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1198,7 +1073,7 @@ class AbstractProxyTestBase(object):
         self.assertEqual(checker._checked, '__ior__')
 
     def test___ior___inplace_checker_allows(self):
-        class Foo(object):
+        class Foo:
             def __init__(self, value):
                 self.value = value
 
@@ -1324,38 +1199,28 @@ class AbstractProxyTestBase(object):
         self.assertRaises(ForbiddenAttribute, _try)
         self.assertEqual(checker._checked, '__setitem__')
 
-    @_skip_if_not_Py2
-    def test___getslice___w_checker_allows(self):  # pragma: no cover
-        target = [0, 1, 2]
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(proxy[1:3], [1, 2])
-        self.assertEqual(checker._checked, self.getslice)
-
     def test___getslice___error_propagates(self):
         class Missing(Exception):
             pass
 
-        class Get(object):
+        class Get:
             def __getitem__(self, x):
                 raise Missing('__getitem__')
 
-            def __getslice__(self, start, stop):  # PY2
-                raise Missing("__getslice__")  # pragma: no cover
         target = Get()
         checker = DummyChecker()
         proxy = self._makeOne(target, checker)
         with self.assertRaisesRegex(Missing,
-                                    self.getslice):
+                                    '__getitem__'):
             proxy[1:2]
 
-        self.assertEqual(checker._checked, self.getslice)
+        self.assertEqual(checker._checked, '__getitem__')
 
     def test___getslice___dne_uses_getitem(self):
         class Missing(Exception):
             pass
 
-        class Get(object):
+        class Get:
             def __getitem__(self, x):
                 raise Missing('__getitem__')
 
@@ -1366,62 +1231,30 @@ class AbstractProxyTestBase(object):
                                     '__getitem__'):
             proxy[1:2]
 
-        self.assertEqual(checker._checked, self.getslice)
-
-    @_skip_if_not_Py2
-    def test___getslice___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = [0, 1, 2]
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertRaises(ForbiddenAttribute, lambda: proxy[0:2])
-        self.assertEqual(checker._checked, '__getslice__')
-
-    @_skip_if_not_Py2
-    def test___setslice___w_checker_allows(self):  # pragma: no cover
-        target = [0, 1, 2]
-        checker = DummyChecker()
-        proxy = self._makeOne(target, checker)
-        proxy[1:3] = [3, 4]
-        self.assertEqual(target, [0, 3, 4])
-        self.assertEqual(checker._checked, '__setslice__')
-
-    @_skip_if_not_Py2
-    def test___setslice___w_checker_forbids(self):  # pragma: no cover
-        from zope.security.interfaces import ForbiddenAttribute
-        target = [0, 1, 2]
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-
-        def _try():
-            proxy[1:3] = [3, 4]
-        self.assertRaises(ForbiddenAttribute, _try)
-        self.assertEqual(checker._checked, '__setslice__')
+        self.assertEqual(checker._checked, '__getitem__')
 
     def test___setslice___error_propagates(self):
         class Missing(Exception):
             pass
 
-        class Set(object):
+        class Set:
             def __setitem__(self, k, v):
                 raise Missing('__setitem__')
 
-            def __setslice__(self, start, stop, value):  # PY2
-                raise Missing("__setslice__")  # pragma: no cover
         target = Set()
         checker = DummyChecker()
         proxy = self._makeOne(target, checker)
         with self.assertRaisesRegex(Missing,
-                                    self.setslice):
+                                    '__setitem__'):
             proxy[1:2] = 1
 
-        self.assertEqual(checker._checked, self.setslice)
+        self.assertEqual(checker._checked, '__setitem__')
 
     def test___setslice___dne_uses_setitem(self):
         class Missing(Exception):
             pass
 
-        class Set(object):
+        class Set:
             def __setitem__(self, k, v):
                 raise Missing('__setitem__')
 
@@ -1432,7 +1265,7 @@ class AbstractProxyTestBase(object):
                                     '__setitem__'):
             proxy[1:2] = 1
 
-        self.assertEqual(checker._checked, self.setslice)
+        self.assertEqual(checker._checked, '__setitem__')
 
     def test___getitem___mapping_hit_w_checker_allows(self):
         target = {'a': 0, 'b': 1, 'c': 2}
@@ -1491,60 +1324,10 @@ class AbstractProxyTestBase(object):
                         z = eval(expr)
                         first = 0
                     else:
-                        self.assertEqual(removeSecurityProxy(eval(expr)), z,
-                                         "x=%r; y=%r; expr=%r" % (x, y, expr))
-
-    @_skip_if_not_Py2
-    def test___unicode___allowed_by_default(self):  # pragma: no cover
-        # https://github.com/zopefoundation/zope.security/issues/10
-        class Foo(object):
-            def __unicode__(self):
-                return u'I am unicode'
-
-        checker = object()  # checker not consulted
-        target = Foo()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(unicode(target), u'I am unicode')
-        self.assertEqual(unicode(target), unicode(proxy))
-
-    @_skip_if_not_Py2
-    def test___unicode___falls_through_to_str_by_default(self):  # pragma: no cover # noqa: E501 line too long
-        # https://github.com/zopefoundation/zope.security/issues/10
-        class Foo(object):
-            def __str__(self):
-                return 'I am str'
-
-        checker = object()  # checker not consulted
-        target = Foo()
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(unicode(target), u'I am str')
-        self.assertIsInstance(unicode(target), unicode)
-        self.assertEqual(unicode(target), unicode(proxy))
-        self.assertIsInstance(unicode(proxy), unicode)
-
-    @_skip_if_not_Py2
-    def test___unicode___falls_through_to_str_even_if_str_not_allowed(self):  # pragma: no cover # noqa: E501 line too long
-        # https://github.com/zopefoundation/zope.security/issues/10
-        # Note that this is inconsistent with str() and probably not a good
-        # idea overall, so this test is strictly a regression test.
-        from zope.security.interfaces import ForbiddenAttribute
-
-        class Foo(object):
-            def __str__(self):
-                return 'I am str'
-
-        target = Foo()
-        checker = DummyChecker(ForbiddenAttribute)
-        proxy = self._makeOne(target, checker)
-        self.assertEqual(unicode(target), u'I am str')
-        self.assertIsInstance(unicode(target), unicode)
-
-        # Asking for the unicode of the proxy silently falls through
-        # to the str without any checks
-        self.assertEqual(unicode(target), unicode(proxy))
-
-        # And set str itself is checked and proxied
-        self.assertIn("<security proxied", str(proxy))
+                        self.assertEqual(
+                            removeSecurityProxy(eval(expr)),
+                            z,
+                            "x={!r}; y={!r}; expr={!r}".format(x, y, expr))
 
 
 @unittest.skipIf(PURE_PYTHON,
@@ -1659,7 +1442,7 @@ class ProxyPyTests(AbstractProxyTestBase,
         self.assertIs(self, getObjectPy(self))
 
     def test_get_reduce(self):
-        class Reduce(object):
+        class Reduce:
             def __reduce__(self):
                 return 1
 
@@ -1672,7 +1455,7 @@ class ProxyPyTests(AbstractProxyTestBase,
         self.assertEqual(2, proxy.__reduce_ex__(2))
 
     def test__module__(self):
-        class WithModule(object):
+        class WithModule:
             __module__ = 'foo'
 
         module = WithModule()
@@ -1680,7 +1463,7 @@ class ProxyPyTests(AbstractProxyTestBase,
         self.assertEqual(WithModule.__module__, proxy.__module__)
 
 
-class DummyChecker(object):
+class DummyChecker:
     _proxied = _checked = None
 
     def __init__(self, raising=None, allowed=()):
@@ -1731,7 +1514,7 @@ class Test_isinstance(unittest.TestCase):
         return isinstance(object, cls)
 
     def test_w_unproxied_object(self):
-        class Foo(object):
+        class Foo:
             pass
         target = Foo()
         self.assertTrue(self._callFUT(target, Foo))
@@ -1741,7 +1524,7 @@ class Test_isinstance(unittest.TestCase):
         from zope.security.checker import Checker
         from zope.security.proxy import Proxy
 
-        class Foo(object):
+        class Foo:
             pass
         target = Foo()
         proxy = Proxy(target, Checker({}))
@@ -1751,7 +1534,7 @@ class Test_isinstance(unittest.TestCase):
 
 # pre-geddon
 
-class Checker(object):
+class Checker:
 
     ok = 1
 
@@ -1808,16 +1591,6 @@ class Something:
     def __len__(self):
         return 42
 
-    def __nonzero__(self):  # PY2
-        return 1  # pragma: no cover
-
-    def __getslice__(self, i, j):  # PY2
-        return [42]  # pragma: no cover
-
-    def __setslice__(self, i, j, value):  # PY2
-        if value != [42]:  # pragma: no cover
-            raise AssertionError("Value should be [42]")
-
     def __contains__(self, x):
         return x == 42
 
@@ -1934,13 +1707,6 @@ class ProxyFactoryTests(unittest.TestCase):
     def testNextFail(self):
         self.shouldFail(self.p.next)
 
-    @_skip_if_not_Py2
-    def testCompareOK(self):  # pragma: no cover
-        self.assertEqual(cmp(self.p, self.x), 0)
-
-#    def testCompareFail(self):
-#        self.shouldFail(cmp, self.p, self.x)
-
     def testHashOK(self):
         self.assertEqual(hash(self.p), hash(self.x))
 
@@ -1959,11 +1725,6 @@ class ProxyFactoryTests(unittest.TestCase):
     def testLenFail(self):
         self.shouldFail(len, self.p)
 
-    @_skip_if_not_Py2
-    def testSliceOK(self):  # pragma: no cover
-        from zope.security.proxy import removeSecurityProxy
-        self.assertEqual(removeSecurityProxy(self.p[:]), [42])
-
     def testSliceFail(self):
         self.shouldFail(lambda: self.p[:])
 
@@ -1992,7 +1753,7 @@ class ProxyFactoryTests(unittest.TestCase):
     def testProxiedClassicClassAsDictKey(self):
         from zope.security.proxy import ProxyFactory
 
-        class C(object):
+        class C:
             pass
         d = {C: C()}
         pC = ProxyFactory(C, self.c)
@@ -2001,15 +1762,13 @@ class ProxyFactoryTests(unittest.TestCase):
     def testProxiedNewClassAsDictKey(self):
         from zope.security.proxy import ProxyFactory
 
-        class C(object):
+        class C:
             pass
         d = {C: C()}
         pC = ProxyFactory(C, self.c)
         self.assertEqual(d[pC], d[C])
 
     unops = ["-x", "+x", "abs(x)", "~x", "int(x)", "float(x)"]
-    if PYTHON2:
-        unops.append("long(x)")  # pragma: no cover
 
     def _make_eval(self, expr, locs):
         def _eval(*args):
@@ -2024,8 +1783,6 @@ class ProxyFactoryTests(unittest.TestCase):
         from zope.security.proxy import ProxyFactory
         from zope.security.proxy import removeSecurityProxy
         self.c.unproxied_types = {str, int, float}
-        if PYTHON2:
-            self.c.unproxied_types.add(long)  # pragma: no cover
 
         for expr in self.unops:
             x = 1
@@ -2034,20 +1791,9 @@ class ProxyFactoryTests(unittest.TestCase):
             x = ProxyFactory(1, self.c)
             z = eval(expr)
             self.assertEqual(removeSecurityProxy(z), y,
-                             "x=%r; expr=%r" % (x, expr))
+                             "x={!r}; expr={!r}".format(x, expr))
             self.shouldFail(self._make_eval(expr, locals()), x)
 
-    @_skip_if_not_Py2
-    def test_odd_unops(self):  # pragma: no cover
-        # unops that don't return a proxy
-        P = self.c.proxy
-        for func in (
-                hex, oct,
-                # lambda x: not x,
-        ):
-            self.assertEqual(func(P(100)), func(100))
-            self.shouldFail(func, P(100))
-
     binops = [
         "x+y", "x-y", "x*y", "x/y", "divmod(x, y)", "x**y", "x//y",
         "x<<y", "x>>y", "x&y", "x|y", "x^y",
@@ -2064,8 +1810,10 @@ class ProxyFactoryTests(unittest.TestCase):
                         z = eval(expr)
                         first = 0
                     else:
-                        self.assertEqual(removeSecurityProxy(eval(expr)), z,
-                                         "x=%r; y=%r; expr=%r" % (x, y, expr))
+                        self.assertEqual(
+                            removeSecurityProxy(eval(expr)),
+                            z,
+                            "x={!r}; y={!r}; expr={!r}".format(x, y, expr))
                         self.shouldFail(self._make_eval(expr, locals()), x, y)
 
     def test_inplace(self):
@@ -2097,69 +1845,6 @@ class ProxyFactoryTests(unittest.TestCase):
             pa **= 2
         self.shouldFail(doit2)
 
-    @_skip_if_not_Py2
-    def test_coerce(self):  # pragma: no cover
-        from zope.security.proxy import removeSecurityProxy
-        P = self.c.proxy
-
-        x = P(1)
-        y = P(2)
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertIs(b, y)
-
-        x = P(1)
-        y = P(2.1)
-        a, b = coerce(x, y)
-        self.assertEqual(removeSecurityProxy(a), 1.0)
-        self.assertIs(b, y)
-        self.assertIs(type(removeSecurityProxy(a)), float)
-        self.assertIs(b, y)
-
-        x = P(1.1)
-        y = P(2)
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertEqual(removeSecurityProxy(b), 2.0)
-        self.assertIs(a, x)
-        self.assertIs(type(removeSecurityProxy(b)), float)
-
-        x = P(1)
-        y = 2
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertIs(b, y)
-
-        x = P(1)
-        y = 2.1
-        a, b = coerce(x, y)
-        self.assertIs(type(removeSecurityProxy(a)), float)
-        self.assertIs(b, y)
-
-        x = P(1.1)
-        y = 2
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertIs(type(removeSecurityProxy(b)), float)
-
-        x = 1
-        y = P(2)
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertIs(b, y)
-
-        x = 1.1
-        y = P(2)
-        a, b = coerce(x, y)
-        self.assertIs(a, x)
-        self.assertIs(type(removeSecurityProxy(b)), float)
-
-        x = 1
-        y = P(2.1)
-        a, b = coerce(x, y)
-        self.assertIs(type(removeSecurityProxy(a)), float)
-        self.assertIs(b, y)
-
     def test_iterate_interface(self):
         # This used to work on Python 2, but fail on Python 3.
         # See https://github.com/zopefoundation/zope.interface/issues/141
@@ -2257,14 +1942,11 @@ 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 importlib import reload as _reload
 
         from zope.location.location import LocationProxy
 
         import zope.security
-        try:
-            from importlib import reload as _reload
-        except ImportError:  # pragma: PY2
-            _reload = reload  # noqa: F821 undefined name 'reload'
 
         # This attribute is set when zope.security.decorator is imported, to
         # show that it will be set too, if zope.security.proxy is imported
diff --git a/src/zope/security/tests/test_simpleinteraction.py b/src/zope/security/tests/test_simpleinteraction.py
index b5b5c4a..4fefddf 100644
--- a/src/zope/security/tests/test_simpleinteraction.py
+++ b/src/zope/security/tests/test_simpleinteraction.py
@@ -16,7 +16,7 @@
 import unittest
 
 
-class RequestStub(object):
+class RequestStub:
 
     def __init__(self, principal=None):
         self.principal = principal
diff --git a/src/zope/security/tests/test_simplepolicies.py b/src/zope/security/tests/test_simplepolicies.py
index e55d0e3..391f942 100644
--- a/src/zope/security/tests/test_simplepolicies.py
+++ b/src/zope/security/tests/test_simplepolicies.py
@@ -14,7 +14,7 @@
 import unittest
 
 
-class ConformsToIInteraction(object):
+class ConformsToIInteraction:
 
     def _getTargetClass(self):
         raise NotImplementedError("Subclass responsibility")
@@ -48,7 +48,7 @@ class ParanoidSecurityPolicyTests(unittest.TestCase,
         self.assertEqual(policy.participations, [])
 
     def test_ctor_w_participations(self):
-        class Participation(object):
+        class Participation:
             interaction = None
         p1, p2, p3 = Participation(), Participation(), Participation()
         policy = self._makeOne(p1, p2, p3)
@@ -58,19 +58,19 @@ class ParanoidSecurityPolicyTests(unittest.TestCase,
         self.assertTrue(p3.interaction is policy)
 
     def test_add_w_foreign_participation(self):
-        class Participation(object):
+        class Participation:
             interaction = object()
         policy = self._makeOne()
         self.assertRaises(ValueError, policy.add, Participation())
 
     def test_remove_w_foreign_participation(self):
-        class Participation(object):
+        class Participation:
             interaction = object()
         policy = self._makeOne()
         self.assertRaises(ValueError, policy.remove, Participation())
 
     def test_remove(self):
-        class Participation(object):
+        class Participation:
             interaction = None
         p1, p2, p3 = Participation(), Participation(), Participation()
         policy = self._makeOne(p1, p2, p3)
@@ -90,7 +90,7 @@ class ParanoidSecurityPolicyTests(unittest.TestCase,
     def test_checkPermission_w_non_public_only_system_user(self):
         from zope.security._definitions import system_user
 
-        class Participation(object):
+        class Participation:
             interaction = None
             principal = system_user
         policy = self._makeOne(Participation())
@@ -99,7 +99,7 @@ class ParanoidSecurityPolicyTests(unittest.TestCase,
         self.assertTrue(policy.checkPermission(permission, target))
 
     def test_checkPermission_w_non_public_other_user(self):
-        class Participation(object):
+        class Participation:
             interaction = None
             principal = object()
         policy = self._makeOne(Participation())
diff --git a/src/zope/security/tests/test_zcml.py b/src/zope/security/tests/test_zcml.py
index db04952..366ee4c 100644
--- a/src/zope/security/tests/test_zcml.py
+++ b/src/zope/security/tests/test_zcml.py
@@ -16,7 +16,7 @@ import unittest
 from zope.security.interfaces import PUBLIC_PERMISSION_NAME as zope_Public
 
 
-class ConformsToIFromUnicode(object):
+class ConformsToIFromUnicode:
 
     def test_class_conforms_to_IFromUnicode(self):
         from zope.interface.verify import verifyClass
@@ -152,7 +152,7 @@ class Test_redefinePermission(unittest.TestCase):
     def test_wo_existing_mapping(self):
         z_context = DummyZCMLContext()
 
-        class Context(object):
+        class Context:
             pass
         context = z_context.context = Context()
         after = object()
@@ -162,7 +162,7 @@ class Test_redefinePermission(unittest.TestCase):
     def test_w_existing_mapping_wo_existing_key(self):
         z_context = DummyZCMLContext()
 
-        class Context(object):
+        class Context:
             pass
         context = z_context.context = Context()
         mapping = context.permission_mapping = {}
@@ -174,7 +174,7 @@ class Test_redefinePermission(unittest.TestCase):
     def test_w_existing_mapping_w_existing_key(self):
         z_context = DummyZCMLContext()
 
-        class Context(object):
+        class Context:
             pass
         context = z_context.context = Context()
         mapping = context.permission_mapping = {}
@@ -185,7 +185,7 @@ class Test_redefinePermission(unittest.TestCase):
         self.assertIs(context.permission_mapping['before.permission'], after)
 
 
-class DummyZCMLContext(object):
+class DummyZCMLContext:
 
     def __init__(self):
         self._actions = []
diff --git a/src/zope/security/tests/test_zcml_functest.py b/src/zope/security/tests/test_zcml_functest.py
index 3f5991a..5186586 100644
--- a/src/zope/security/tests/test_zcml_functest.py
+++ b/src/zope/security/tests/test_zcml_functest.py
@@ -18,7 +18,7 @@ import unittest
 
 
 def configfile(s):
-    return io.StringIO(u"""<configure
+    return io.StringIO("""<configure
       xmlns='http://namespaces.zope.org/zope'
       i18n_domain='zope'>
       %s
@@ -283,7 +283,7 @@ def defineDirectives():
 
     import zope.security
     XMLConfig('meta.zcml', zope.security)()
-    xmlconfig(io.StringIO(u"""<configure
+    xmlconfig(io.StringIO("""<configure
         xmlns='http://namespaces.zope.org/zope'
         i18n_domain='zope'>
        <permission id="zope.Extravagant" title="extravagant" />
@@ -307,7 +307,7 @@ class TestRequireDirective(unittest.TestCase):
         setUp()
         defineDirectives()
 
-        class B(object):
+        class B:
             def m1(self):
                 raise AssertionError("Never called")
 
@@ -528,34 +528,39 @@ class TestRequireDirective(unittest.TestCase):
         self.assertDeclaration(declaration, m1P=P1, m2P=P1)
 
     def testMimicOnly(self):
-        declaration = ('''<class class="%s">
+        declaration = ('''<class class="{}">
                             <require
-                                permission="%s"
+                                permission="{}"
                                 attributes="m1 m2"/>
                           </class>
-                          <class class="%s">
-                            <require like_class="%s" />
+                          <class class="{}">
+                            <require like_class="{}" />
                           </class>
-                          ''' % (_pfx("test_base"), P1,
-                                 _pfx("test_class"), _pfx("test_base")))
+                          '''.format(_pfx("test_base"), P1,
+                                     _pfx("test_class"), _pfx("test_base")))
         # m1 and m2 are in the interface, so should be set, and m3 should not:
         self.assertDeclaration(declaration,
                                m1P=P1, m2P=P1)
 
     def testMimicAsDefault(self):
-        declaration = ('''<class class="%s">
+        declaration = (
+            '''<class class="{}">
                             <require
-                                permission="%s"
+                                permission="{}"
                                 attributes="m1 m2"/>
                           </class>
-                          <class class="%s">
-                            <require like_class="%s" />
+                          <class class="{}">
+                            <require like_class="{}" />
                             <require
-                                permission="%s"
+                                permission="{}"
                                 attributes="m2 m3"/>
                           </class>
-                          ''' % (_pfx("test_base"), P1,
-                                 _pfx("test_class"), _pfx("test_base"), P2))
+                          '''.format(
+                                _pfx("test_base"),
+                                P1,
+                                _pfx("test_class"),
+                                _pfx("test_base"),
+                                P2))
 
         # m1 and m2 are in the interface, so should be set, and m3 should not:
         self.assertDeclaration(declaration,
@@ -565,8 +570,6 @@ class TestRequireDirective(unittest.TestCase):
 def apply_declaration(declaration):
     '''Apply the xmlconfig machinery.'''
     from zope.configuration.xmlconfig import xmlconfig
-    if isinstance(declaration, bytes):
-        declaration = declaration.decode("utf-8")  # pragma: no cover PY2
     return xmlconfig(io.StringIO(declaration))
 
 
@@ -577,7 +580,7 @@ def make_dummy():
     global IDummy
 
     class IDummy(Interface):
-        perm = zope.security.zcml.Permission(title=u'')
+        perm = zope.security.zcml.Permission(title='')
 
 
 perms = []
diff --git a/src/zope/security/zcml.py b/src/zope/security/zcml.py
index 1f48138..d24e04d 100644
--- a/src/zope/security/zcml.py
+++ b/src/zope/security/zcml.py
@@ -33,13 +33,13 @@ class Permission(Id):
     """
 
     def fromUnicode(self, value):
-        u = super(Permission, self).fromUnicode(value)
+        u = super().fromUnicode(value)
 
         map = getattr(self.context, 'permission_mapping', {})
         return map.get(u, u)
 
     def _validate(self, value):
-        super(Permission, self)._validate(value)
+        super()._validate(value)
 
         if value != zope_Public:
             self.context.action(
@@ -61,8 +61,8 @@ class ISecurityPolicyDirective(Interface):
     """Defines the security policy that will be used for Zope."""
 
     component = GlobalObject(
-        title=u"Component",
-        description=u"Pointer to the object that will handle the security.",
+        title="Component",
+        description="Pointer to the object that will handle the security.",
         required=True)
 
 
@@ -78,22 +78,22 @@ class IPermissionDirective(Interface):
     """Define a new security object."""
 
     id = Id(
-        title=u"ID",
-        description=u"ID as which this object will be known and used.",
+        title="ID",
+        description="ID as which this object will be known and used.",
         required=True)
 
     title = MessageID(
-        title=u"Title",
-        description=u"Provides a title for the object.",
+        title="Title",
+        description="Provides a title for the object.",
         required=True)
 
     description = MessageID(
-        title=u"Description",
-        description=u"Provides a description for the object.",
+        title="Description",
+        description="Provides a description for the object.",
         required=False)
 
 
-def permission(_context, id, title, description=u''):
+def permission(_context, id, title, description=''):
     from zope.component.zcml import utility
 
     from zope.security.interfaces import IPermission
@@ -106,13 +106,13 @@ class IRedefinePermission(Interface):
     """Define a permission to replace another permission."""
 
     from_ = Permission(
-        title=u"Original permission",
-        description=u"Original permission ID to redefine.",
+        title="Original permission",
+        description="Original permission ID to redefine.",
         required=True)
 
     to = Permission(
-        title=u"Substituted permission",
-        description=u"Substituted permission ID.",
+        title="Substituted permission",
+        description="Substituted permission ID.",
         required=True)
 
 
diff --git a/tox.ini b/tox.ini
index 761ba12..8a47458 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,31 +4,27 @@
 minversion = 3.18
 envlist =
     lint
-    py27,py27-pure
-    py35,py35-pure
-    py36,py36-pure
     py37,py37-pure
     py38,py38-pure
     py39,py39-pure
     py310,py310-pure
     py311,py311-pure
-    pypy
     pypy3
     docs
     coverage
-    py27-watch, py37-watch
+    py37-watch, py311-watch
 
 [testenv]
 usedevelop = true
 deps =
 setenv =
     pure: PURE_PYTHON=1
-    !pure-!pypy-!pypy3: PURE_PYTHON=0
+    !pure-!pypy3: PURE_PYTHON=0
     ZOPE_INTERFACE_STRICT_IRO=1
     watch: ZOPE_WATCH_CHECKERS=1
 commands =
     zope-testrunner --test-path=src {posargs:-vc}
-    !py27-!pypy: sphinx-build -b doctest -d {envdir}/.cache/doctrees docs {envdir}/.cache/doctest
+    sphinx-build -b doctest -d {envdir}/.cache/doctrees docs {envdir}/.cache/doctest
 extras =
     test
     docs
@@ -64,6 +60,7 @@ deps =
 
 [testenv:isort-apply]
 basepython = python3
+skip_install = true
 commands_pre =
 deps =
     isort