bpo-39102: Increase Enum performance up to 10x times (3x average)

Lib/inspect.py

@@ -2420,7 +2420,7 @@ class _ParameterKind(enum.IntEnum):
     VAR_KEYWORD = 4
 
     def __str__(self):
-        return self._name_
+        return self.name
 
     @property
     def description(self):

Lib/re.py

@@ -153,17 +153,17 @@ class RegexFlag(enum.IntFlag):
     DEBUG = sre_compile.SRE_FLAG_DEBUG # dump pattern after compilation
 
     def __repr__(self):
-        if self._name_ is not None:
-            return f're.{self._name_}'
-        value = self._value_
+        if self.name is not None:
+            return f're.{self.name}'
+        value = self.value
         members = []
         negative = value < 0
         if negative:
             value = ~value
         for m in self.__class__:
-            if value & m._value_:
-                value &= ~m._value_
-                members.append(f're.{m._name_}')
+            if value & m.value:
+                value &= ~m.value
+                members.append(f're.{m.name}')
         if value:
             members.append(hex(value))
         res = '|'.join(members)

Lib/test/test_dynamicclassattribute.py

@@ -295,6 +295,36 @@ def spam(self):
         self.assertEqual(Foo.__dict__['spam'].__doc__, "a new docstring")
 
 
+class TestSetClassAttr(unittest.TestCase):
+    def test_set_class_attr(self):
+        class Foo:
+            def __init__(self, value):
+                self._value = value
+                self._spam = 'spam'
+
+            @DynamicClassAttribute
+            def value(self):
+                return self._value
+
+            spam = DynamicClassAttribute(
+                lambda s: s._spam,
+                alias='my_shiny_spam'
+            )
+
+        self.assertFalse(hasattr(Foo, 'value'))
+        self.assertFalse(hasattr(Foo, 'name'))
+
+        foo_bar = Foo('bar')
+        value_desc = Foo.__dict__['value']
+        value_desc.set_class_attr(Foo, foo_bar)
+        self.assertIs(Foo.value, foo_bar)
+        self.assertEqual(Foo.value.value, 'bar')
+
+        foo_baz = Foo('baz')
+        Foo.my_shiny_spam = foo_baz
+        self.assertIs(Foo.spam, foo_baz)
+        self.assertEqual(Foo.spam.spam, 'spam')
+
 
 if __name__ == '__main__':
     unittest.main()