Suppose I have a **large** matrix with columns in this way`[A1,B1,C1,A2,B2,C2,A3,B3,C3]`. How rearrange it to format of `[A1,A2,A3,B1,B2,B3,C1,C2,C3]`. In this case, it is step between two A is three, what if the step size is n?

```
x=np.array(
[[ 1.1, 2.1 , 3.1,  1.2,  2.2, 3.2],
 [ 4.1, 5.1,  6.1,  4.2,  5.2, 6.2]])

x[:,[0,3,1,4,2,5]] # is there a way to do it not manually?

```

desired output

```
array([[1.1, 1.2, 2.1, 2.2, 3.1, 3.2],
       [4.1, 4.2, 5.1, 5.2, 6.1, 6.2]])

```