Adding value of single numpy array to all columns in other numpy array

This can be done with a little help from broadcasting by adding a new axis to B (either with None or with np.newaxis) so that they have compatible shapes, and B is broadcastable accross the larger array A:

A + B[:,None]

array([[11, 12, 13, 14],
       [25, 26, 27, 28],
       [39, 40, 41, 42]])