如何循环遍历n维稀疏矩阵(由自己的类创建)？

class SparseMatrix:
    def __init__(self, matrix):
        self.matrix = matrix

    def traverse(self, matrix=None, indices=None):
        if matrix is None:
            matrix = self.matrix
            indices = []

        if isinstance(matrix, list):
            for i, item in enumerate(matrix):
                indices.append(i)
                self.traverse(item, indices)
                indices.pop()

        else:
            print("Index:", indices, "Value:", matrix)

# 创建一个3维稀疏矩阵
matrix = [
    [
        [1, 0, 0],
        [0, 2, 0],
        [0, 0, 3]
    ],
    [
        [4, 0, 0],
        [0, 5, 0],
        [0, 0, 6]
    ]
]

# 创建稀疏矩阵对象
sparse_matrix = SparseMatrix(matrix)

# 遍历稀疏矩阵
sparse_matrix.traverse()