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

The error message `'numpy.ndarray' object has no attribute 'index'` typically occurs when you try to call the `index()` method on a NumPy array. However, unlike lists in Python, NumPy arrays don't have an `index()` method.

To find the index of an element in a NumPy array, you can use the `numpy.where()` function. Here's an example:

import numpy as np

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

This will output `(array([2]),)`, which indicates that the value `3` is located at index `2` in the array.