issues

What happened?

I'm looking to rename the values of indices of an existing dataset, for both regular and multi-index. i.e. you might start with a dataset with and index [1,2,3] and you want to rename those to ["foo", "bar", "bar"].

I appear to be able to rename a couple using the method I've written, though renaming a second multi-index in the same xr.Dataset causes a ValueError I am struggling to interpret.

cannot re-index or align objects with conflicting indexes found for the following dimensions: 'x' (2 conflicting indexes) Conflicting indexes may occur when - they relate to different sets of coordinate and/or dimension names - they don't have the same type - they may be used to reindex data along common dimensions

What did you expect to happen?

I start with the xr.Datset:

xarray.DataArray (x: 6, y: 6, z: 3)> array(...) Coordinates: * x (x) object MultiIndex * x_one (x) object 'a' 'a' 'b' 'b' 'c' 'c' * x_two (x) int64 0 1 0 1 0 1 * y (y) object MultiIndex * y_one (y) object 'a' 'a' 'b' 'b' 'c' 'c' * y_two (y) int64 0 1 0 1 0 1 * z (z) int64 0 1 2

And remap the z, x_one, and y_one values to:

xarray.DataArray (x: 6, y: 6, z: 3)> array(...) Coordinates: * x (x) object MultiIndex * x_one (x) object 'aa' 'aa' 'bb' 'bb' 'cc' 'cc' * x_two (x) int64 0 1 0 1 0 1 * y (y) object MultiIndex * y_one (y) object 'aa' 'aa' 'bb' 'bb' 'cc' 'cc' * y_two (y) int64 0 1 0 1 0 1 * z (z) <U4 'zero' 'one' 'two'

Minimal Complete Verifiable Example

```Python import numpy as np import pandas as pd import xarray as xr

def map_coords(ds, *, name, mapping): """ Takes a xarray dataset's coordinate values and updates them with the given the provided mapping.

Can handle both regular indices and multi-level indices.

ds: the datasets
name: name of the coordinate to update
mapping: dictionary, key of old value, value of new value.
"""
coord = ds.coords[name]
old_values = coord.values.tolist()
new_values = [mapping[v] for v in old_values]
ds.coords[name] = xr.DataArray(new_values, coords=coord.coords)
ds.coords[name].attrs = dict(coord.attrs)

midx = pd.MultiIndex.from_product([list("abc"), [0, 1]], names=("x_one", "x_two")) midy = pd.MultiIndex.from_product([list("abc"), [0, 1]], names=("y_one", "y_two"))

mda = xr.DataArray(np.random.rand(6, 6, 3), [("x", midx), ("y", midy), ("z", range(3))])

map_coords(mda, name="z", mapping={0: "zero", 1: "one", 2: "two"}). # success map_coords(mda, name="x_one", mapping={"a": "aa", "b": "bb", "c": "cc"}) # success map_coords(mda, name="y_one", mapping={"a": "aa", "b": "bb", "c": "cc"}) # ValueError ```

MVCE confirmation

• [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
• [X] Complete example — the example is self-contained, including all data and the text of any traceback.
• [X] Verifiable example — the example copy & pastes into an IPython prompt or Binder notebook, returning the result.
• [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

Relevant log output

Python Traceback (most recent call last): File "./main.py", line 30, in <module> map_coords(mda, name="y_one", mapping={"a": "aa", "b": "bb", "c": "cc"}) File "./main.py", line 20, in map_coords ds.coords[name] = xr.DataArray(new_values, coords=coord.coords) File "./.venv/lib/python3.10/site-packages/xarray/core/coordinates.py", line 32, in __setitem__ self.update({key: value}) File "./.venv/lib/python3.10/site-packages/xarray/core/coordinates.py", line 162, in update coords, indexes = merge_coords( File "./.venv/lib/python3.10/site-packages/xarray/core/merge.py", line 561, in merge_coords aligned = deep_align( File "./.venv/lib/python3.10/site-packages/xarray/core/alignment.py", line 827, in deep_align aligned = align( File "./.venv/lib/python3.10/site-packages/xarray/core/alignment.py", line 764, in align aligner.align() File "./.venv/lib/python3.10/site-packages/xarray/core/alignment.py", line 550, in align self.assert_no_index_conflict() File "./.venv/lib/python3.10/site-packages/xarray/core/alignment.py", line 319, in assert_no_index_conflict raise ValueError( ValueError: cannot re-index or align objects with conflicting indexes found for the following dimensions: 'x' (2 conflicting indexes) Conflicting indexes may occur when - they relate to different sets of coordinate and/or dimension names - they don't have the same type - they may be used to reindex data along common dimensions

Anything else we need to know?

I may also not be doing this remapping in the best way, this has been the easiest way I've found to do it. So maybe part of the problem is that, so open to alternative methods as well.

Thanks.

Environment