concatenate two arrays in python with alternating the columns in numpy

Question

How to concatenate two arrays in numpy python by taking first column from the first array and fisrt column from the second, then second column from first and second from the other, etc..? that is if I have A=[a1 a2 a3] and B=[b1 b2 b3] I want the resulting array to be [a1 b1 a2 b2 a3 b3]

Answer 1

Few approaches with stacking could be suggested -

np.vstack((A,B)).ravel('F')
np.stack((A,B)).ravel('F')
np.ravel([A,B],'F')

Sample run -

In [291]: A
Out[291]: array([3, 5, 6])

In [292]: B
Out[292]: array([13, 15, 16])

In [293]: np.vstack((A,B)).ravel('F')
Out[293]: array([ 3, 13,  5, 15,  6, 16])

In [294]: np.ravel([A,B],'F')
Out[294]: array([ 3, 13,  5, 15,  6, 16])