import itertools


def _chunk(iterable, size):
    """Split an iterable into chunks of a fixed size."""
    # We're going to use some star magic to chunk the iterable. We create a
    # copy of the iterator size times, then pull a value from each to form a
    # chunk. The last chunk may have some trailing Nones if the length of the
    # iterable isn't a multiple of size, so we filter them out.

    args = (iter(iterable),) * size

    return (
        # pylint: disable=star-args
        itertools.takewhile(lambda x: x is not None, group)
        for group in itertools.zip_longest(*args)
    )