Spark Matrix multiplication with python

I am trying to do matrix multiplication using Apache Spark and Python.

Here is my data

from pyspark.mllib.linalg.distributed import RowMatrix

My RDD of vectors

rows_1 = sc.parallelize([[1, 2], [4, 5], [7, 8]])
rows_2 = sc.parallelize([[1, 2], [4, 5]])

My maxtrix

mat1 = RowMatrix(rows_1)
mat2 = RowMatrix(rows_2)

I would like to do something like this:

mat = mat1 * mat2