How to add an extra column to a NumPy array

Question

Let’s say I have a NumPy array, a:

a = np.array([
    [1, 2, 3],
    [2, 3, 4]
    ])

And I would like to add a column of ze

Answer 1

For me, the next way looks pretty intuitive and simple.

zeros = np.zeros((2,1)) #2 is a number of rows in your array.   
b = np.hstack((a, zeros))