I have a matrix
matrix = [[0.0] * 4] * 4
it looks like:
0    0    0   0
0    0    0   0
0    0    0   0
0    0    0   0
I'm trying to add an element to the second row, third column so that the matrix looks like this:
0    0    0   0
0    0    3   0
0    0    0   0
0    0    0   0
When I do
matrix[1][2] = 3
it gives:
0    0    3   0
0    0    3   0
0    0    3   0
0    0    3   0
How do I fix this?
