用python创建一个空的四维数组

可以使用NumPy的`numpy.empty()`函数来创建空的四维数组。这个函数创建一个指定形状的数组，但是不会初始化数组元素的值，因此数组元素的值是随机的。以下是一个创建空的四维数组的示例代码：

import numpy as np

# 创建一个形状为(2, 3, 4, 5)的空四维数组
arr = np.empty((2, 3, 4, 5))

# 输出数组形状和元素
print(arr.shape) # (2, 3, 4, 5)
print(arr)

输出：

(2, 3, 4, 5)
[[[[ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]]

  ...

  [[ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]]]


 [[[ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]]

  ...

  [[ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]
   [ 1.28822975e-231  1.28822975e-231  1.28822975e-231  1.28822975e-231
      1.28822975e-231]]]]

可以看到，创建的四维数组的形状为`(2, 3, 4, 5)`，并且数组元素的值是随机的。