import itertools


def subsequences(iterable, seq=2):
    """Return subsequences of an iterable

    Each element in the generator will be a tuple of `seq` elements that were
    ordered in the iterable.
    """
    iters = itertools.tee(iterable, seq)
    for i, itr in enumerate(iters):
        for _ in range(i):
            next(itr, None)
    return zip(*iters)