Class SequenceClass

Lib/test/test_functools.py:1094–1101

    # Test reduce()'s use of iterators.
    def test_iterator_usage(self):
        class SequenceClass:
            def __init__(self, n):
                self.n = n
            def __getitem__(self, i):
                if 0 <= i < self.n:
                    return i
                else:
                    raise IndexError

        from operator import add
        self.assertEqual(self.reduce(add, SequenceClass(5)), 10)