issues

What happened?

We execute ds.groupby('clifford').mean(). The resulting Dataset is different depending whether the optional package flox is installed or not.

What did you expect to happen?

The result should be the same

Minimal Complete Verifiable Example

```Python import xarray as xr d={'coords': {'bit_index': {'dims': ('bit_index',), 'attrs': {'name': 'bit_index', 'units': 'a.u.', 'standard_name': 'bit_index', 'long_name': 'bit_index', 'label': 'bit_index'}, 'data': [0, 1]}, 'index': {'dims': ('index',), 'attrs': {'name': 'index', 'units': '', 'standard_name': 'index', 'long_name': 'index', 'label': 'index'}, 'data': [0, 6, 8, 10, 14]}, 'clifford': {'dims': ('index',), 'attrs': {}, 'data': [1, 1, 4, 10, 4]}, 'pauli': {'dims': ('index',), 'attrs': {}, 'data': [12, 12, 6, 12, 6]}, 'pauli_value': {'dims': ('index',), 'attrs': {}, 'data': [1, 1, 1, 1, 1]}}, 'attrs': {}, 'dims': {'bit_index': 2, 'index': 5}, 'data_vars': {'counts': {'dims': ('bit_index', 'index'), 'attrs': {'name': 'counts', 'units': '', 'standard_name': 'Counts', 'long_name': 'Counts', 'label': 'Counts'}, 'data': [[18, 30, 45, 70, 38], [382, 370, 355, 330, 362]]}}}

ds=xr.Dataset.from_dict(d)
ds.groupby('clifford').mean() ```

(execute with both flox installed and flox not installed) ``` """ With flox <xarray.Dataset> Dimensions: (bit_index: 2, clifford: 3) Coordinates: * bit_index (bit_index) int32 0 1 * clifford (clifford) int64 1 4 10 Data variables: counts (bit_index, clifford) float64 24.0 41.5 70.0 376.0 358.5 330.0 """

""" No flox <xarray.Dataset> Dimensions: (bit_index: 2, clifford: 3) Coordinates: * bit_index (bit_index) int32 0 1 * clifford (clifford) int64 1 4 10 Data variables: counts (clifford, bit_index) float64 24.0 376.0 41.5 358.5 70.0 330.0 """ ```

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.
• [X] Recent environment — the issue occurs with the latest version of xarray and its dependencies.

Relevant log output

No response

Anything else we need to know?

This is probably related to #7546

Environment

The documentation for xarray.plot.dataarray_plot.pcolormesh (and several other methods) states: ... center : float, optional The value at which to center the colormap. Passing this value implies use of a diverging colormap. Setting it to ``False`` prevents use of a diverging colormap. robust : bool, optional ... The False argument for center is a valid argument, but was not included in the type annotations. In this PR we update the type annotations.