import numpy as np
arr = np.array([[1, 2, 3],[4, 5, 6],[7, 8, 9]])
print(arr)
col = np.array([12, 13, 14])
col = col.reshape(3, 1)
arr = np.append(arr, col, axis=1)
print(arr)
'''
run:
[[1 2 3]
[4 5 6]
[7 8 9]]
[[ 1 2 3 12]
[ 4 5 6 13]
[ 7 8 9 14]]
'''