Creating and populating a 2D array with elements of an existing array?

Question

Python

i have array [1,2,3,4,5,6,7,8,9] and i want to get

how to implement this?

Answer 1

a = [1,2,3,4,5,6,7,8,9]
[a[i*3:i*3+3] for i in range(len(a)//3)]