Fixed #30902 -- Added __str__() for model choice enums.

Allows expected behavior when cast to str, also matching behaviour of
created instances with those fetched from the DB.

Thanks to Simon Charette, Nick Pope, and Shai Berger for reviews.

2 files changed, 13 insertions, 1 deletions

diff --git a/django/db/models/enums.py b/django/db/models/enums.py
index bbe362a6ab..ae20ef6d93 100644
--- a/django/db/models/enums.py
+++ b/django/db/models/enums.py
@@ -60,7 +60,13 @@ class ChoicesMeta(enum.EnumMeta):
 
 class Choices(enum.Enum, metaclass=ChoicesMeta):
     """Class for creating enumerated choices."""
-    pass
+
+    def __str__(self):
+        """
+        Use value when cast to str, so that Choices set as model instance
+        attributes are rendered as expected in templates and similar contexts.
+        """
+        return str(self.value)
 
 
 class IntegerChoices(int, Choices):
diff --git a/tests/model_enums/tests.py b/tests/model_enums/tests.py
index 6b4bd6e7fd..e1810e673a 100644
--- a/tests/model_enums/tests.py
+++ b/tests/model_enums/tests.py
@@ -143,6 +143,12 @@ class ChoicesTests(SimpleTestCase):
                 APPLE = 1, 'Apple'
                 PINEAPPLE = 1, 'Pineapple'
 
+    def test_str(self):
+        for test in [Gender, Suit, YearInSchool, Vehicle]:
+            for member in test:
+                with self.subTest(member=member):
+                    self.assertEqual(str(test[member.name]), str(member.value))
+
 
 class Separator(bytes, models.Choices):
     FS = b'\x1c', 'File Separator'