issue_comments: 1239064150

From discussions in #4825 and elsewhere (e.g., https://github.com/pydata/xarray/issues/6607#issuecomment-1126587818), could we say that we're going towards a consensus that the index vs. coordinate API should be decoupled wherever possible?

If that's the case, then set_coords() shouldn't create any index, but it could be chained with set_index() if necessary (or swap_dims() can be used instead).

Apparently set_coords() never created an index? I tested @johnomotani's example back to v0.14. Before v2022.6.0, there was a source of confusion where the Dataset and DataArray reprs still showed an * for the dimension coordinate while it had no index. This is fixed in v2022.6.0 where the reprs are now consistent: no * and no index. Does this solve the issue here?

@johnomotani from your example it looks like the two alternatives below would produce the desired result with v2022.6.0:

• ds.set_index(x='b')
• ds.rename(b='x').set_coords('x').set_index(x='x')

I would encourage using the latter. It is more verbose but clearer (each method is explicit).

Note also that Xarray now also supports non-dimension coordinates with an index. Once #6971 is merged, renaming "b" to "x" won't be needed. Instead you'll be able to do something like:

ds = xr.Dataset() ds['a'] = ('x', np.linspace(0,1)) ds['b'] = ('x', np.linspace(3,4)) ds = ds.set_coords('b').set_xindex('b') ds.sel(b=...)