How to read matrix input into a 2-D list in python 3?

Question

I am trying to input a 3X3 matrix in 2D list input format is

1 2 3
4 5 6
7 8 9

Answer 1

If you're reading from a file:

arraylist = []
for line in file:
innerlist = []
for number in line.split():
innerlist.append(int(number))
arraylist.append(innerlist)