#!/usr/bin/env python3

# importing Numpy package
import numpy as np

matrix = np.array([[1, 2, 3],
                   [2, 4, 6],
                   [3, 8, 9]])
# Retorna los elementos de la diagonal
diag=matrix.diagonal()
print(diag) # [1 4 9]

print(type(diag)) # <class 'numpy.ndarray'>
print(diag.dtype) # int64
print(diag.shape) # (3,)

# Return diagonal one above the main diagonal
print(matrix.diagonal(offset=1)) # [2 6]
# Return diagonal one below the main diagonal
print(matrix.diagonal(offset=-1)) # [2 8]