Chunking n adjacent items in a list

ichunk.py

#! /usr/bin/env python

from itertools import izip_longest

def ichunk(iterable, n):
    '''Chunk n adjacent elements in the iterable. For example
       ichunk((1,2,3,4,5,6), 2) -> (1,2),(3,4),(5,6)'''

    iters = (iter(iterable),) * n
    return izip_longest(*iters, fillvalue=None)


if '__main__' == __name__:

    x = range(20)

    for i in range (1, 21):
        print list(ichunk(x, i))