Upgrade mypy to 1.15 (#10041)

Seems easy locally; maybe too easy and something will break in CI...

Author: max-sixty

.github/workflows/ci-additional.yaml

@@ -116,7 +116,7 @@ jobs:
           python xarray/util/print_versions.py
       - name: Install mypy
         run: |
-          python -m pip install "mypy==1.13" --force-reinstall
+          python -m pip install "mypy==1.15" --force-reinstall
 
       - name: Run mypy
         run: |
@@ -167,7 +167,7 @@ jobs:
           python xarray/util/print_versions.py
       - name: Install mypy
         run: |
-          python -m pip install "mypy==1.13" --force-reinstall
+          python -m pip install "mypy==1.15" --force-reinstall
 
       - name: Run mypy
         run: |

xarray/core/groupby.py

@@ -1606,8 +1606,7 @@ def reduce_array(ar: DataArray) -> DataArray:
         return self.map(reduce_array, shortcut=shortcut)
 
 
-# https://github.com/python/mypy/issues/9031
-class DataArrayGroupBy(  # type: ignore[misc]
+class DataArrayGroupBy(
     DataArrayGroupByBase,
     DataArrayGroupByAggregations,
     ImplementsArrayReduce,
@@ -1774,8 +1773,7 @@ def assign(self, **kwargs: Any) -> Dataset:
         return self.map(lambda ds: ds.assign(**kwargs))
 
 
-# https://github.com/python/mypy/issues/9031
-class DatasetGroupBy(  # type: ignore[misc]
+class DatasetGroupBy(
     DatasetGroupByBase,
     DatasetGroupByAggregations,
     ImplementsDatasetReduce,

xarray/core/indexing.py

@@ -480,7 +480,7 @@ def __init__(self, key: tuple[slice | np.ndarray[Any, np.dtype[np.generic]], ...
                     )
                 if ndim is None:
                     ndim = k.ndim  # type: ignore[union-attr]
-                elif ndim != k.ndim:
+                elif ndim != k.ndim:  # type: ignore[union-attr]
                     ndims = [k.ndim for k in key if isinstance(k, np.ndarray)]
                     raise ValueError(
                         "invalid indexer key: ndarray arguments "

xarray/core/resample.py

@@ -232,8 +232,7 @@ def _interpolate(self, kind="linear", **kwargs) -> T_Xarray:
         )
 
 
-# https://github.com/python/mypy/issues/9031
-class DataArrayResample(  # type: ignore[misc]
+class DataArrayResample(
     Resample["DataArray"], DataArrayGroupByBase, DataArrayResampleAggregations
 ):
     """DataArrayGroupBy object specialized to time resampling operations over a
@@ -375,8 +374,7 @@ def asfreq(self) -> DataArray:
         return self.mean(None if self._dim is None else [self._dim])
 
 
-# https://github.com/python/mypy/issues/9031
-class DatasetResample(  # type: ignore[misc]
+class DatasetResample(
     Resample["Dataset"], DatasetGroupByBase, DatasetResampleAggregations
 ):
     """DatasetGroupBy object specialized to resampling a specified dimension"""