import itertools


def pairwise_full_circle(sequence):
    """Yields 2-tuples of two sequential items from the sequene.

    The final value contains a pair of the last item from the sequence
    combined with the very first item from the sequence.
    """
    this, ahead = itertools.tee(sequence)
    ahead = itertools.chain(ahead, [next(ahead)])
    return zip(this, ahead)