How to construct matrix from vectors?

[Nasser M. Abbasi]

I just started to learn some python today for first time,
so be easy on me.

I am having some trouble figuring how do the problem shown in this link

http://12000.org/my_notes/mma_matlab_control/KERNEL/KEse44.htm

Given 4 column vectors, v1,v2,v3,v4, each is 3 rows.

I want to use these to construct matrix mat, which is

       [[v1,v2],
        [v3,v4]]

So the resulting matrix is as shown in the link.  i.e.
it will be 6 rows and 2 columns.

This is what I tried:

import numpy as np
v1=np.array([1,2,3]);
v2=np.array([4,5,6]);
v3=np.array([7,8,9]);
v4=np.array([10,11,12]);

And now I get stuck, I tried

m=np.array([[v1,v2],[v3,v4]])  #no good

Also

m=np.array([v1,v2,v3,v4])
m.shape
    Out[153]: (4L, 3L)
m.T

array([[ 1,  4,  7, 10],
        [ 2,  5,  8, 11],
        [ 3,  6,  9, 12]])

Not what I want.

I need to get the shape as in the above link, 6 rows by 2 columns,
where each column vector is stacked as shown.  I also tried

v1=np.array([1,2,3]); v1.shape=3,1
v2=np.array([4,5,6]); v2.shape=3,1
v3=np.array([7,8,9]); v3.shape=3,1
v4=np.array([10,11,12]); v4.shape=3,1
mat=np.array([[v1,v2],[v3,v4]])

What is the correct way to do this in Python?

thanks,
--Nasser