索引 [::-1] 以同时反转所有 2D 数组行和所有 3D 和 4D 数组列和行 Python

Question

How do you get indexing [::-1] to reverse ALL 2D array rows and ALL 3D and 4D array columns and rows simultaneously? I can only get indexing [::-1] to reverse 2D array columns. Python

import numpy as np

randomArray = np.round(10*np.random.rand(5,4))
sortedArray = np.sort(randomArray,axis=1)
reversedArray = sortedArray[::-1]
# reversedArray = np.flip(sortedArray,axis=1)

print('Random Array:')
print(randomArray,'\n')
print('Sorted Array:')
print(sortedArray,'\n')
print('Reversed Array:')
print(reversedArray)

Answer 1

You can reverse a dimensions of a numpy array depending on where you place the ::-1 .

Lets take a 3D array. For reversing the first dimension:

reversedArray = sortedArray[::-1,:,:]

For reversing the second dimension:

reversedArray = sortedArray[:,::-1,:]

For reversing the third dimension:

reversedArray = sortedArray[:,:,::-1]