r""" makes a string from an integer bounding box

def bbox_str(bbox, pad=4, sep=', '):
    r""" makes a string from an integer bounding box """
    if bbox is None:
        return 'None'
    fmtstr = sep.join(['%' + six.text_type(pad) + 'd'] * 4)
    return '(' + fmtstr % tuple(bbox) + ')'