issue_comments: 1498463195

Here's a question.

In #7561, I implement Grouper objects that don't have any information of the variable we're grouping by. So the future API would be:

python data.groupby({ "x0": xr.BinGrouper(bins=pd.IntervalIndex.from_breaks(coords["x_vertices"])), # binning "y": xr.UniqueGrouper(labels=["a", "b", "c"]), # categorical, data.y is dask-backed "time": xr.TimeResampleGrouper(freq="MS") }, )

Does this look OK or do we want to support passing the DataArray or variable name as a by kwarg:
python xr.BinGrouper(by="x0", bins=pd.IntervalIndex.from_breaks(coords["x_vertices"]))

This syntax would support passing DataArray in by so xr.UniqueGrouper(by=data.y) for example. Is that an important usecase to support? In #7561, I create new ResolvedGrouper objects that do contain by as a DataArray always, so it's really a question of exposing that to the user.

PS: Pandas has a key kwarg for a column name. So following that would mean

python data.groupby([ xr.BinGrouper("x0", bins=pd.IntervalIndex.from_breaks(coords["x_vertices"])), # binning xr.UniqueGrouper("y", labels=["a", "b", "c"]), # categorical, data.y is dask-backed xr.TimeResampleGrouper("time", freq="MS") ], )