Generalize reduce() to work with iterators.
NEEDS DOC CHANGES.
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index 66f40c1..5584587 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -385,4 +385,17 @@
except OSError:
pass
+ # Test reduces()'s use of iterators.
+ def test_builtin_reduce(self):
+ from operator import add
+ self.assertEqual(reduce(add, SequenceClass(5)), 10)
+ self.assertEqual(reduce(add, SequenceClass(5), 42), 52)
+ self.assertRaises(TypeError, reduce, add, SequenceClass(0))
+ self.assertEqual(reduce(add, SequenceClass(0), 42), 42)
+ self.assertEqual(reduce(add, SequenceClass(1)), 0)
+ self.assertEqual(reduce(add, SequenceClass(1), 42), 42)
+
+ d = {"one": 1, "two": 2, "three": 3}
+ self.assertEqual(reduce(add, d), "".join(d.keys()))
+
run_unittest(TestCase)