Generator of slices which represent a mosaic indexing of an iterable object

mosaic.py

def mosaic(iterable_shape, subdivided_shape):
    """
    Return a generator of slices that represent a subdivided indexing of an iterable of specified shape.
    
    """
    shape = subdivided_shape
    if len(iterable_shape) != len(shape):
        raise ValueError('Array shape and resulting shape mismatch, broadcasting not supported.')
    
    # iterate through this array with shape (shape)
    subdomain = [[slice(itt*shape[dim], itt*shape[dim] + shape[dim]) for itt in
                  range(int(math.ceil(iterable_shape[dim]/float(shape[dim]))))] for
                 dim in range(len(shape))]
    return itertools.product(*subdomain)