Python scipy.io write a mat file of n by 1

I need to save a .mat file from python. The mat file should be a cell array of n by 1. The code below does what I need except the output mat file is 1 by n.

import scipy.io as sio
import numpy as np

Label = ['A','Bob','C']
mat_file = {'label_mat':np.array(Label, dtype=object)}
sio.savemat(r'./test.mat', mat_file)

How do I generate the desired n by 1 file?

Answer

Just do a list of lists.

import scipy.io as sio
import numpy as np

Label = [['A'],['Bob'],['C']]
mat_file = {'label_mat':np.array(Label, dtype=object)}
sio.savemat(r'./test.mat', mat_file)