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

The error message "'numpy.ndarray' object has no attribute 'unsqueeze'" typically occurs when you try to use the `unsqueeze` method on a NumPy array. However, NumPy arrays do not have an `unsqueeze` method by default.

If you want to add an additional dimension to a NumPy array, you can use the `numpy.newaxis` keyword along with slicing. Here's an example:

import numpy as np

arr = np.array([1, 2, 3])  # Shape: (3,)
new_arr = arr[:, np.newaxis]  # Shape: (3, 1)

print(new_arr)

In this example, we use `np.newaxis` to add a new axis at the second dimension. The resulting shape of `new_arr` will be `(3, 1)`.

If you provide more specific information about your use case, I can provide a more tailored solution.