id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type 955617411,MDU6SXNzdWU5NTU2MTc0MTE=,5646,Level names in multi-level index are ignored,688461,closed,0,,,3,2021-07-29T08:56:48Z,2022-09-27T12:34:21Z,2022-09-27T12:34:20Z,NONE,,,,"**What happened**: The difference of the level names in multi-level index is silently ignored. **What you expected to happen**: Error message. **Minimal Complete Verifiable Example**: ```python import xarray as xr a = xr.DataArray([[1]], dims = [""x"", ""y""]) b = a.stack({""z"": [""x"", ""y""]}) c = a.rename({""x"": ""not-x"", ""y"": ""not-y""}).stack({""z"": [""not-x"", ""not-y""]}) xr.testing.assert_allclose(b, c) print(b == c, ""\n"") print(b.coords == c.coords, ""\n"") print(b + c, ""\n"") print(c + b, ""\n"") ``` Output: ``` array([ True]) Coordinates: * z (z) MultiIndex - x (z) int64 0 - y (z) int64 0 True array([2]) Coordinates: * z (z) MultiIndex - x (z) int64 0 - y (z) int64 0 array([2]) Coordinates: * z (z) MultiIndex - not-x (z) int64 0 - not-y (z) int64 0 ``` **Environment**:
Output of xr.show_versions() INSTALLED VERSIONS ------------------ commit: None python: 3.9.1 (tags/v3.9.1:1e5d33e, Dec 7 2020, 17:08:21) [MSC v.1927 64 bit (AMD64)] python-bits: 64 OS: Windows OS-release: 10 machine: AMD64 processor: Intel64 Family 6 Model 165 Stepping 5, GenuineIntel byteorder: little LC_ALL: None LANG: ru_RU.UTF-8 LOCALE: ('Russian_Russia', '1251') libhdf5: 1.12.0 libnetcdf: None xarray: 0.18.2 pandas: 1.3.0 numpy: 1.21.1 scipy: 1.6.0 netCDF4: None pydap: None h5netcdf: None h5py: 3.1.0 Nio: None zarr: None cftime: None nc_time_axis: None PseudoNetCDF: None rasterio: None cfgrib: None iris: None bottleneck: None dask: None distributed: None matplotlib: 3.4.2 cartopy: None seaborn: None numbagg: None pint: None setuptools: 57.4.0 pip: 21.1.3 conda: None pytest: None IPython: None sphinx: None
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