iterk.py

NO_FILLVALUE = object()


def iterk(iterable, k, fillvalue=NO_FILLVALUE):
    """Iterate over *k* entries at a time

    Make an iterator that yields *k* elements of *iterable* at a time. If the
    length of *iterable* is not a multiple of *k*, *fillvalue* will be used to
    fill out the remaining elements. If no *fillvalue* is set, the remaining
    elements will be ignored.

    >>> list(iterk(range(10), k=2))
    [(0, 1), (2, 3), (4, 5), (6, 7), (8, 9)]
    >>> list(iterk(range(10), k=4))
    [(0, 1, 2, 3), (4, 5, 6, 7)]
    >>> list(iterk(range(10), k=4, fillvalue=None))
    [(0, 1, 2, 3), (4, 5, 6, 7), (8, 9, None, None)]
    >>> list(iterk(range(10), k=4, fillvalue=-1))
    [(0, 1, 2, 3), (4, 5, 6, 7), (8, 9, -1, -1)]
    
    This implementation was inspired by the *grouper* recipe
    in the *itertools* module.
    """
    args = [iter(iterable)] * k
    if fillvalue is NO_FILLVALUE:
        return zip(*args)
    return zip_longest(fillvalue=fillvalue, *args)

Her må jeg erklære mig enig med Michael.