How to prove that Matrix $M$ is a Markov Matrix?

Question

I am learning the PageRanks algorithm, and came across a question which demands to prove that:

1. given a Markov matrix $M$, the following resulting matrix $A$ will also be a Markov matrix:

2. the product of two Markov matrices is a Markov matrix.

How can one prove these two statements with an example in Python? Does anyone here has an idea?

Thank you in advance!