GH-98363: Presize the list for batched() by rhettinger · Pull Request #98419 · python/cpython

I'm thinking of leaving this as is. The current PR matches the behavior of the pure python version and the strange iterator works the same way with other tools:

>>> it = zip(range(10), A())
>>> list(it)
[(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]
>>> list(it)
[(8, 8), (9, 9)]

>>> it = enumerate(A())
>>> list(it)
[(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)]
>>> next(it)
(7, 8)
>>> next(it)
(8, 9)

That said, I'm not really sure about this one and could easily be persuaded to add a Py_CLEAR(bo->it) to the code path for the short list.