Issue #9930: Remove an unnecessary type check in wrap_binaryfunc_r;
this was causing reversed method calls like float.__radd__(3.0, 1) to
return NotImplemented instead of the expected numeric value.
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 0979880..47fecfe 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -285,6 +285,11 @@
         self.assertEqual(repr(a), "234.5")
         self.assertEqual(a.prec, 12)
 
+    def test_explicit_reverse_methods(self):
+        # see issue 9930
+        self.assertEqual(complex.__radd__(3j, 4.0), complex(4.0, 3.0))
+        self.assertEqual(float.__rsub__(3.0, 1), -2.0)
+
     @support.impl_detail("the module 'xxsubtype' is internal")
     def test_spam_lists(self):
         # Testing spamlist operations...