numpy.unique_inverse — NumPy v2.3 Manual (original) (raw)

numpy.unique_inverse(x)[source]#

Find the unique elements of x and indices to reconstruct x.

This function is an Array API compatible alternative to:

np.unique(x, return_inverse=True, equal_nan=False, sorted=False)

but returns a namedtuple for easier access to each output.

Note

This function currently always returns a sorted result, however, this could change in any NumPy minor release.

Parameters:

xarray_like

Input array. It will be flattened if it is not already 1-D.

Returns:

outnamedtuple

The result containing:

• values - The unique elements of an input array.
• inverse_indices - The indices from the set of unique elements that reconstruct x.

See also

unique

Find the unique elements of an array.

Examples

import numpy as np x = [1, 1, 2] uniq = np.unique_inverse(x) uniq.values array([1, 2]) uniq.inverse_indices array([0, 0, 1])