From ab60fdda7fbc6d341c70de66c9724a1ddf8c9b9e Mon Sep 17 00:00:00 2001
From: Ethan Furman <ethan@stoneleaf.us>
Date: Thu, 13 Apr 2023 08:31:03 -0700
Subject: [PATCH 1/3]                     [3.11] gh-103479: [Enum] require
 __new__ to be considered a data type (GH-103495)

a mixin must either have a __new__ method, or be a dataclass, to be interpreted as a data-type.
                    (cherry picked from commit a6f95941a3d686707fb38e0f37758e666f25e180)

                    Co-authored-by: Ethan Furman <ethan@stoneleaf.us>
---
 Doc/howto/enum.rst    |  8 +++++---
 Lib/enum.py           |  3 ++-
 Lib/test/test_enum.py | 11 +++++++----
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/Doc/howto/enum.rst b/Doc/howto/enum.rst
index 32310692fe56ed..dbd8d4fa9231ee 100644
--- a/Doc/howto/enum.rst
+++ b/Doc/howto/enum.rst
@@ -837,17 +837,19 @@ Some rules:
 4. When another data type is mixed in, the :attr:`value` attribute is *not the
    same* as the enum member itself, although it is equivalent and will compare
    equal.
-5. %-style formatting:  ``%s`` and ``%r`` call the :class:`Enum` class's
+5. A ``data type`` is a mixin that defines :meth:`__new__`, or a
+   :class:`~dataclasses.dataclass`
+6. %-style formatting:  ``%s`` and ``%r`` call the :class:`Enum` class's
    :meth:`__str__` and :meth:`__repr__` respectively; other codes (such as
    ``%i`` or ``%h`` for IntEnum) treat the enum member as its mixed-in type.
-6. :ref:`Formatted string literals <f-strings>`, :meth:`str.format`,
+7. :ref:`Formatted string literals <f-strings>`, :meth:`str.format`,
    and :func:`format` will use the enum's :meth:`__str__` method.
 
 .. note::
 
    Because :class:`IntEnum`, :class:`IntFlag`, and :class:`StrEnum` are
    designed to be drop-in replacements for existing constants, their
-   :meth:`__str__` method has been reset to their data types
+   :meth:`__str__` method has been reset to their data types'
    :meth:`__str__` method.
 
 When to use :meth:`__new__` vs. :meth:`__init__`
diff --git a/Lib/enum.py b/Lib/enum.py
index 84ae339d0d4020..0ef6559b3c6bd6 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -981,6 +981,7 @@ def _find_data_repr_(mcls, class_name, bases):
 
     @classmethod
     def _find_data_type_(mcls, class_name, bases):
+        # a datatype has a __new__ method, or a __dataclass_fields__ attribute
         data_types = set()
         base_chain = set()
         for chain in bases:
@@ -993,7 +994,7 @@ def _find_data_type_(mcls, class_name, bases):
                     if base._member_type_ is not object:
                         data_types.add(base._member_type_)
                         break
-                elif '__new__' in base.__dict__ or '__init__' in base.__dict__:
+                elif '__new__' in base.__dict__:
                     if isinstance(base, EnumType):
                         continue
                     data_types.add(candidate or base)
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 51dd66bea0c42c..2d615edee580d2 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -2667,13 +2667,14 @@ class Foo:
             a: int
         class Entries(Foo, Enum):
             ENTRY1 = 1
+        self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: ha hah!>')
+        self.assertTrue(Entries.ENTRY1.value == Foo(1), Entries.ENTRY1.value)
         self.assertTrue(isinstance(Entries.ENTRY1, Foo))
         self.assertTrue(Entries._member_type_ is Foo, Entries._member_type_)
         self.assertTrue(Entries.ENTRY1.value == Foo(1), Entries.ENTRY1.value)
         self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: Foo(a=1)>')
 
-    def test_repr_with_init_data_type_mixin(self):
-        # non-data_type is a mixin that doesn't define __new__
+    def test_repr_with_init_mixin(self):
         class Foo:
             def __init__(self, a):
                 self.a = a
@@ -2682,9 +2683,9 @@ def __repr__(self):
         class Entries(Foo, Enum):
             ENTRY1 = 1
         #
-        self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: Foo(a=1)>')
+        self.assertEqual(repr(Entries.ENTRY1), 'Foo(a=1)')
 
-    def test_repr_and_str_with_non_data_type_mixin(self):
+    def test_repr_and_str_with_no_init_mixin(self):
         # non-data_type is a mixin that doesn't define __new__
         class Foo:
             def __repr__(self):
@@ -2790,6 +2791,8 @@ def __new__(cls, c):
 
     def test_init_exception(self):
         class Base:
+            def __new__(cls, *args):
+                return object.__new__(cls)
             def __init__(self, x):
                 raise ValueError("I don't like", x)
         with self.assertRaises(TypeError):

From 102b7f8ac6defe7c16d6f438922ced74cf3a7bd1 Mon Sep 17 00:00:00 2001
From: Ethan Furman <ethan@stoneleaf.us>
Date: Thu, 13 Apr 2023 09:58:19 -0700
Subject: [PATCH 2/3] remove mention of dataclass

---
 Doc/howto/enum.rst | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Doc/howto/enum.rst b/Doc/howto/enum.rst
index dbd8d4fa9231ee..55f0dfb4c48c38 100644
--- a/Doc/howto/enum.rst
+++ b/Doc/howto/enum.rst
@@ -837,8 +837,7 @@ Some rules:
 4. When another data type is mixed in, the :attr:`value` attribute is *not the
    same* as the enum member itself, although it is equivalent and will compare
    equal.
-5. A ``data type`` is a mixin that defines :meth:`__new__`, or a
-   :class:`~dataclasses.dataclass`
+5. A ``data type`` is a mixin that defines :meth:`__new__`.
 6. %-style formatting:  ``%s`` and ``%r`` call the :class:`Enum` class's
    :meth:`__str__` and :meth:`__repr__` respectively; other codes (such as
    ``%i`` or ``%h`` for IntEnum) treat the enum member as its mixed-in type.

From faff581517e19529986b44577203fe55f6f9be10 Mon Sep 17 00:00:00 2001
From: Ethan Furman <ethan@stoneleaf.us>
Date: Thu, 13 Apr 2023 10:58:11 -0700
Subject: [PATCH 3/3] restore mention of dataclass

---
 Lib/enum.py           | 4 ++--
 Lib/test/test_enum.py | 4 +---
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/Lib/enum.py b/Lib/enum.py
index 0ef6559b3c6bd6..5b175820972f4c 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -981,7 +981,7 @@ def _find_data_repr_(mcls, class_name, bases):
 
     @classmethod
     def _find_data_type_(mcls, class_name, bases):
-        # a datatype has a __new__ method, or a __dataclass_fields__ attribute
+        # a datatype has a __new__ method
         data_types = set()
         base_chain = set()
         for chain in bases:
@@ -994,7 +994,7 @@ def _find_data_type_(mcls, class_name, bases):
                     if base._member_type_ is not object:
                         data_types.add(base._member_type_)
                         break
-                elif '__new__' in base.__dict__:
+                elif '__new__' in base.__dict__ or '__dataclass_fields__' in base.__dict__:
                     if isinstance(base, EnumType):
                         continue
                     data_types.add(candidate or base)
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 2d615edee580d2..397bb849d00aba 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -2667,8 +2667,6 @@ class Foo:
             a: int
         class Entries(Foo, Enum):
             ENTRY1 = 1
-        self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: ha hah!>')
-        self.assertTrue(Entries.ENTRY1.value == Foo(1), Entries.ENTRY1.value)
         self.assertTrue(isinstance(Entries.ENTRY1, Foo))
         self.assertTrue(Entries._member_type_ is Foo, Entries._member_type_)
         self.assertTrue(Entries.ENTRY1.value == Foo(1), Entries.ENTRY1.value)
@@ -2679,7 +2677,7 @@ class Foo:
             def __init__(self, a):
                 self.a = a
             def __repr__(self):
-                return f'Foo(a={self.a!r})'
+                return 'Foo(a=%r)' % self._value_
         class Entries(Foo, Enum):
             ENTRY1 = 1
         #

<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html xmlns='http://www.w3.org/1999/xhtml'>
<head>
<title>pFad - Phonifier reborn</title>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />
</head>
<body>
<h1>Pfad - The Proxy pFad of &#169; 2024 Garber Painting. All rights reserved.</h1>


<!-- Disclaimer -->
<p>Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.</p>
<br>
<p>Alternative Proxies:</p><p><a href="http://rainy.clevelandohioweatherforecast.com/php-proxy/index.php?q=https://patch-diff.githubusercontent.com/raw/python/cpython/pull/103514.patch" target="_blank">Alternative Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/index.php?u=https://patch-diff.githubusercontent.com/raw/python/cpython/pull/103514.patch" target="_blank">pFad Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v3index.php?u=https://patch-diff.githubusercontent.com/raw/python/cpython/pull/103514.patch" target="_blank">pFad v3 Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v4index.php?u=https://patch-diff.githubusercontent.com/raw/python/cpython/pull/103514.patch" target="_blank">pFad v4 Proxy</a></p></body>
</html>