Drop support for Python 2.7 up to 3.6.

setup.py

@@ -103,7 +103,7 @@ def header_dirs_for_dep(distname, headername):  # 3 and 4
     ]
 
 
-class IncludeDirs(object):
+class IncludeDirs:
     dirs = None
 
     def __getattribute__(self, name):
@@ -118,19 +118,14 @@ def __iter__(self):
         return iter(self.dirs)
 
 
-if str is bytes and hasattr(sys, 'pypy_version_info'):
-    # zope.proxy, as of 4.3.5, cannot compile on PyPy2 7.3.0
-    # because it uses cl_dict in a PyClassObject, which does not exist.
-    ext_modules = []
-else:
-    ext_modules = [
-        Extension(
-            "zope.container._zope_container_contained",
-            [os.path.join("src", "zope", "container",
-                          "_zope_container_contained.c")],
-            include_dirs=IncludeDirs(),
-        ),
-    ]
+ext_modules = [
+    Extension(
+        "zope.container._zope_container_contained",
+        [os.path.join("src", "zope", "container",
+                      "_zope_container_contained.c")],
+        include_dirs=IncludeDirs(),
+    ),
+]
 
 setup_requires = [
     'persistent >= 4.1.0',
@@ -140,7 +135,6 @@ def __iter__(self):
 
 install_requires = setup_requires + [
     'BTrees',
-    'six',
     'zope.cachedescriptors',
     'zope.component',
     'zope.deferredimport',
@@ -199,11 +193,7 @@ def __iter__(self):
           'Intended Audience :: Developers',
           'License :: OSI Approved :: Zope Public License',
           'Programming Language :: Python',
-          'Programming Language :: Python :: 2',
-          'Programming Language :: Python :: 2.7',
           'Programming Language :: Python :: 3',
-          'Programming Language :: Python :: 3.5',
-          'Programming Language :: Python :: 3.6',
           'Programming Language :: Python :: 3.7',
           'Programming Language :: Python :: 3.8',
           'Programming Language :: Python :: 3.9',
@@ -234,12 +224,5 @@ def __iter__(self):
       tests_require=extras['test'],
       include_package_data=True,
       zip_safe=False,
-      python_requires=', '.join([
-          '>=2.7',
-          '!=3.0.*',
-          '!=3.1.*',
-          '!=3.2.*',
-          '!=3.3.*',
-          '!=3.4.*',
-      ]),
+      python_requires='>=3.7',
       )

src/zope/container/_proxy.py

@@ -36,13 +36,13 @@ class ContainedProxyBase(AbstractPyProxyBase, Persistent):
     __slots__ = ('_wrapped', '__parent__', '__name__', '__weakref__')
 
     def __new__(cls, obj):
-        inst = super(ContainedProxyBase, cls).__new__(cls, obj)
+        inst = super().__new__(cls, obj)
         inst.__parent__ = None
         inst.__name__ = None
         return inst
 
     def __init__(self, obj):
-        super(ContainedProxyBase, self).__init__(obj)
+        super().__init__(obj)
         self.__parent__ = None
         self.__name__ = None
 
@@ -94,7 +94,7 @@ def __getattribute__(self, name):
         ):
             return object.__getattribute__(self, name)
 
-        return super(ContainedProxyBase, self).__getattribute__(name)
+        return super().__getattribute__(name)
 
     def __setattr__(self, name, value):
         if _special_name(name):
@@ -103,7 +103,7 @@ def __setattr__(self, name, value):
             # themselves
             return Persistent.__setattr__(self, name, value)
 
-        return super(ContainedProxyBase, self).__setattr__(name, value)
+        return super().__setattr__(name, value)
 
 
 @use_c_impl

src/zope/container/_util.py

@@ -157,19 +157,9 @@ def find_impl():
             if not isinstance(v, types.FunctionType):
                 continue
 
-            # Somewhat surprisingly, on Python 2, while
-            # ``Class.function`` results in a
-            # ``types.UnboundMethodType`` (``instancemethed``) object,
-            # ``Class.__dict__["function"]`` returns a
-            # ``types.FunctionType``, just like ``Class.function``
-            # (and the dictionary access, of course) does on Python 3.
-            # The upshot is, we don't need different version-dependent
-            # code. Hooray!
             if new_globals is None:
                 new_globals = v.__globals__.copy()
                 new_globals[py_impl.__name__] = py_impl
-            # On Python 2, all arguments are optional, but an Python 3, all
-            # are required.
             v = types.FunctionType(
                 v.__code__,
                 new_globals,

src/zope/container/_zope_container_contained.c

@@ -78,13 +78,8 @@ typedef struct {
 /* Incude the proxy C source */
 #include "_zope_proxy_proxy.c"
 
-#ifdef PY3K
-  #define MAKE_PYSTRING(s) PyUnicode_FromString(s)
-  #define MAKE_STRING(name) PyBytes_AS_STRING(PyUnicode_AsUTF8String(name))
-#else
-  #define MAKE_PYSTRING(s) PyString_FromString(s)
-  #define MAKE_STRING(name) PyString_AS_STRING(name)
-#endif
+#define MAKE_PYSTRING(s) PyUnicode_FromString(s)
+#define MAKE_STRING(name) PyBytes_AS_STRING(PyUnicode_AsUTF8String(name))
 
 #define SPECIAL(NAME) (                        \
     *(NAME) == '_' &&                          \
@@ -316,13 +311,8 @@ MOD_INIT(_zope_container_contained)
     empty_tuple = PyTuple_New(0);
 
   /* Initialize the PyPersist_C_API and the type objects. */
-#ifdef PY3K
-    cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCapsule_Import(
-                "persistent.cPersistence.CAPI", 0);
-#else
-    cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCObject_Import(
-                "persistent.cPersistence", "CAPI");
-#endif
+  cPersistenceCAPI = (cPersistenceCAPIstruct *)PyCapsule_Import(
+              "persistent.cPersistence.CAPI", 0);
 
   if (cPersistenceCAPI == NULL)
     return MOD_ERROR_VAL;

src/zope/container/constraints.py

@@ -47,7 +47,7 @@
    >>> checkObject(c1, "Zbob", None)
    Traceback (most recent call last):
    ...
-   Invalid: Names can not start with Z
+   zope.interface.exceptions.Invalid: Names can not start with Z
 
    We can also express constaints on the containers an object can be
    added to. We do this by setting a field constraint on an object's
@@ -76,7 +76,7 @@
    >>> checkObject(c1, "bob", O())
    Traceback (most recent call last):
    ...
-   ConstraintNotSatisfied: (C1, '__parent__')
+   zope.schema._bootstrapinterfaces.ConstraintNotSatisfied: (C1, '__parent__')
 
    Note that the validation error isn't very informative. For that
    reason, it's better for constraints to raise Invalid errors when they
@@ -98,7 +98,7 @@
    >>> checkObject(c1, "bob", O())
    Traceback (most recent call last):
    ...
-   Invalid: What, no x?
+   zope.interface.exceptions.Invalid: What, no x?
 
    >>> c1.x = 1
    >>> checkObject(c1, "bob", O())
@@ -246,7 +246,7 @@ def factory(container, name, factory):
         """
 
 
-class _TypesBased(object):
+class _TypesBased:
 
     @readproperty
     def types(self):

src/zope/container/constraints.rst

@@ -59,15 +59,15 @@ If we try to use other containers or folders, we'll get errors:
     >>> checkObject(Container(), 'x', Buddy())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidContainerType: ...
+    zope.container.interfaces.InvalidContainerType: ...
 
     >>> checkFactory(Container(), 'x', Factory(Buddy))
     False
 
     >>> checkObject(BuddyFolder(), 'x', Contained())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidItemType: ...
+    zope.container.interfaces.InvalidItemType: ...
 
     >>> checkFactory(BuddyFolder(), 'x', Factory(Contained))
     False
@@ -90,7 +90,7 @@ could have defined these in the opposite order:
     >>> checkObject(Contacts(), 'x', Buddy())
     ... # doctest: +ELLIPSIS
     Traceback (most recent call last):
-    InvalidItemType: ...
+    zope.container.interfaces.InvalidItemType: ...
 
     >>> checkFactory(Contacts(), 'x', Factory(Buddy))
     False