如何迭代地转置spark rdd的子矩阵？

from pyspark import SparkContext

# 创建SparkContext
sc = SparkContext("local", "Transpose RDD Submatrix")

# 创建一个包含子矩阵的RDD
rdd = sc.parallelize([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

# 定义转置函数
def transpose_submatrix(submatrix):
    # 转置子矩阵
    transposed_submatrix = list(map(list, zip(*submatrix)))
    return transposed_submatrix

# 使用glom()函数将RDD转换为数组，并迭代转置子矩阵
transposed_rdd = rdd.glom().map(transpose_submatrix)

# 打印转置后的RDD
for submatrix in transposed_rdd.collect():
    print(submatrix)

# 停止SparkContext
sc.stop()