import numpy as np
A = (np.arange(9) - 4).reshape((3, 3))
A
array([[-4, -3, -2], [-1, 0, 1], [ 2, 3, 4]])
np.linalg.norm(A)
7.745966692414834
np.trace(np.eye(3))
3.0
A = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
np.linalg.det(A)
-9.51619735392994e-16