python，.unique

In Python, `.unique` is not a built-in method or function. However, the NumPy library has a method called `np.unique()` that returns the unique elements of an array.

Here is an example of how to use `np.unique()`:

import numpy as np

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

Output:

[1 2 3 4 5]

In this example, `np.unique()` takes an array `arr` and returns a new array `unique_arr` with only the unique elements of `arr`.