Enhance issubclass() and PyObject_IsSubclass() so that a tuple is

supported as the second argument. This has the same meaning as
for isinstance(), i.e. issubclass(X, (A, B)) is equivalent
to issubclass(X, A) or issubclass(X, B). Compared to isinstance(),
this patch does not search the tuple recursively for classes, i.e.
any entry in the tuple that is not a class, will result in a
TypeError.

This closes SF patch #649608.

1 files changed, 9 insertions, 0 deletions

diff --git a/Lib/test/test_isinstance.py b/Lib/test/test_isinstance.py
index 8dfb956653..1bb09a6edc 100644
--- a/Lib/test/test_isinstance.py
+++ b/Lib/test/test_isinstance.py
@@ -218,6 +218,15 @@ class TestIsInstanceIsSubclass(unittest.TestCase):
         self.assertEqual(False, issubclass(AbstractChild, Super))
         self.assertEqual(False, issubclass(AbstractChild, Child))
 
+    def test_subclass_tuple(self):
+        # test with a tuple as the second argument classes
+        self.assertEqual(True, issubclass(Child, (Child,)))
+        self.assertEqual(True, issubclass(Child, (Super,)))
+        self.assertEqual(False, issubclass(Super, (Child,)))
+        self.assertEqual(True, issubclass(Super, (Child, Super)))
+        self.assertEqual(False, issubclass(Child, ()))
+        self.assertRaises(TypeError, issubclass, Child, ((Child,),))
+