def is_valid_shape(value):
    """must be a positive integer or a tuple/list of positive integers"""
    if is_int_positive(value):
        return True, value
    elif isinstance(value, tuple) or isinstance(value, list):
        for v in value:
            if not is_int_positive(v):
                return False, value
        return True, value
    else:
        return False, value
must be a positive integer or a tuple/list of positive integers