Python add 1d array to 2d array by column

Question

I have a 1d array and 2d array

a = [4,7,10]
b = [[1,2,3],[4,5,6],[7,8,9]]
a.shape = (2,)
b.shape = (3,3)

I want:

c = [[1,2,3,4],[4,5,6,7],[7,8,9,10]]
c.shape = (3,4)

I tried np.vstack, np.concenrate but all failed

question from:https://stackoverflow.com/questions/65866347/python-add-1d-array-to-2d-array-by-column

Answer 1

You can use numpy.column_stack:

>>> np.column_stack([b,a])
array([[ 1,  2,  3,  4],
       [ 4,  5,  6,  7],
       [ 7,  8,  9, 10]])