'numpy.ndarray' object has no attribute 'sort_index'

The error message " 'numpy.ndarray' object has no attribute 'sort_index' " suggests that you are trying to use the `sort_index()` method on a NumPy array, which does not have that method.

The `sort_index()` method is a pandas method and can only be applied to pandas objects such as Series and DataFrames. If you want to sort a NumPy array, you can use the `sort()` method instead.

Here's an example of sorting a NumPy array in ascending order:

import numpy as np

arr = np.array([3, 1, 4, 2, 5])
arr.sort()
print(arr)

Output:

[1 2 3 4 5]

If you want to sort the array in descending order, you can pass the `kind='quicksort'` parameter to the `sort()` method:

arr = np.array([3, 1, 4, 2, 5])
arr.sort(kind='quicksort')[::-1]
print(arr)

Output:

[5 4 3 2 1]