def pull_pairs(flat):
    """Return a Iterable of pairs of adjacent items in another Iterable

    `flat` should be of even size:
    `len(list(flat)) % 2 == 0`

    >>> list(pull_pairs([1, 2, 3, 4]))
    [(1, 2), (3, 4)]
    """
    it = iter(flat)
    return zip(it, it)