numpy multi-dimensional array
The useful thing about numpy is it can create a multi-dimensional array.
a_mul = np.array([[1,2,3], [4,5,6], [7, 8, 9]])
print(a_mul)
[[1 2 3]
[4 5 6]
[7 8 9]]
If I print(a_mul[0, 1]), what would I get? This means the first row, second column. So, it should be 2.
Likewise, you can print a_mul.shape.
This should return (3, 3) because it is the matrix has three rows and three columns.