def chunk_interslices(nchunks):
    """Make staggered chunks

    Similar to chunk_slices, but pick every nth element instead of
    getting a contiguous patch for each chunk

    Parameters:
        nchunks: how many chunks to make

    Returns:
        a list of (start, stop, step) tuples with length nchunks

    Example:
        >>> chunk_slices(2) == [(0, None, 2), (1, None, 2)]
        True
    """
    ret = [None] * nchunks
    for i in range(nchunks):
        ret[i] = (i, None, nchunks)
    return ret