有没有一种方法可以使用numpy的花式语法简化代码？

Question

我试图使我的代码更高效，如果有更好的方法实现相同的结果，我就很伤心。

import numpy as np

n = 100
arr2D = np.empty((n, n)) #Lets assume its filled with relevant data
arr3D = np.empty((n, n, 3))
for i in range(n):
   for j in range(n):
       arr3D[i, j, 0] = arr2D[i, j]
       arr3D[i, j, 1] = arr2D[i, j]
       arr3D[i, j, 2] = arr2D[i, j]

我基本上是在尝试用2D数组值填充3D数组。