how to append in a numpy array code example

Example 1: np array append

>>> import numpy as np
>>> np.append([[0, 1, 2], [3, 4, 5]],[[6, 7, 8]], axis=0)
array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])

Example 2: numpy python add array

x1 = [1, 2]
x2 = [1, 2]
print(np.add(x1, x2))
# [2, 4]