Change object.__format__(s) where s is non-empty to a TypeError

Lib/test/test_builtin.py

--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -1374,17 +1374,11 @@
         # --------------------------------------------------------------------
         # Issue #7994: object.__format__ with a non-empty format string is
         #  deprecated
-        def test_deprecated_format_string(obj, fmt_str, should_raise_warning):
-            with warnings.catch_warnings(record=True) as w:
-                warnings.simplefilter("always", DeprecationWarning)
+        def test_deprecated_format_string(obj, fmt_str, should_raise):
+            if should_raise:
+                self.assertRaises(TypeError, format, obj, fmt_str)
+            else:
                 format(obj, fmt_str)
-            if should_raise_warning:
-                self.assertEqual(len(w), 1)
-                self.assertIsInstance(w[0].message, DeprecationWarning)
-                self.assertIn('object.__format__ with a non-empty format '
-                              'string', str(w[0].message))
-            else:
-                self.assertEqual(len(w), 0)
 
         fmt_strs = ['', 's']