def is_matrix(iterable):
    """
    Check if a iterable is an matrix (iterable of iterables)

    >>> is_recursive_iter([[1, 2, 3], [5, 6], [9, 10]])
    True
     >>> is_recursive_iter([1, 2, 3])
    False
    """
    if isinstance(iterable, (list, tuple)):
        return all(
            isinstance(i, (list, tuple))
            for i in iterable
        )
    return False