[Python] Swapping rows and columns in Numpy data

import numpy as np

arr = np.arange(9).reshape((3,3))

array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])

arr.T

array([[0, 3, 6],
       [1, 4, 7],
       [2, 5, 8]])

arr.transpose()

array([[0, 3, 6],
       [1, 4, 7],
       [2, 5, 8]])

arr.transpose((1,0))

array([[0, 3, 6],
       [1, 4, 7],
       [2, 5, 8]])

arr.swapaxes(1,0)

array([[0, 3, 6],
       [1, 4, 7],
       [2, 5, 8]])

arr.swapaxes(0,1)

array([[0, 3, 6],
       [1, 4, 7],
       [2, 5, 8]])

np.dot(arr.T,arr)

array([[45, 54, 63],
       [54, 66, 78],
       [63, 78, 93]])

arr3d = np.arange(12).reshape((3,2,2)) 
arr3d

array([[[ 0,  1],
        [ 2,  3]],

       [[ 4,  5],
        [ 6,  7]],

       [[ 8,  9],
        [10, 11]]])

arr3d[0]

array([[0, 1],
       [2, 3]])

arr3d.transpose((0,2,1))

array([[[ 0,  2],
        [ 1,  3]],

       [[ 4,  6],
        [ 5,  7]],

       [[ 8, 10],
        [ 9, 11]]])

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