Upgrade mypy to 1.15

Mypy 1.15 includes fix for <python/mypy#9031>,
allowing several "type: ignore" comments to be removed.

Author: chuckwondo

.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
 
       - name: Run mypy
         run: |
@@ -125,7 +125,7 @@ jobs:
       - name: Upload mypy coverage to Codecov
         uses: codecov/codecov-action@v5.3.1
         with:
-          file: mypy_report/cobertura.xml
+          files: mypy_report/cobertura.xml
           flags: mypy
           env_vars: PYTHON_VERSION
           name: codecov-umbrella
@@ -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
 
       - name: Run mypy
         run: |
@@ -176,7 +176,7 @@ jobs:
       - name: Upload mypy coverage to Codecov
         uses: codecov/codecov-action@v5.3.1
         with:
-          file: mypy_report/cobertura.xml
+          files: mypy_report/cobertura.xml
           flags: mypy-min
           env_vars: PYTHON_VERSION
           name: codecov-umbrella

.pre-commit-config.yaml

@@ -42,23 +42,37 @@ repos:
       - id: prettier
         args: [--cache-location=.prettier_cache/cache]
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.14.1
+    rev: v1.15.0
     hooks:
       - id: mypy
-        # Copied from setup.cfg
-        exclude: "properties|asv_bench"
+        files: "^xarray"
+        exclude: "^xarray/util/generate_.*\\.py$"
         # This is slow and so we take it out of the fast-path; requires passing
         # `--hook-stage manual` to pre-commit
         stages: [manual]
-        additional_dependencies: [
-            # Type stubs
-            types-python-dateutil,
-            types-setuptools,
-            types-PyYAML,
-            types-pytz,
-            typing-extensions>=4.1.0,
-            numpy,
-          ]
+        additional_dependencies:
+          # Type stubs plus additional dependencies from ci/requirements/environment.yml
+          # required in order to satisfy most (ideally all) type checks.  This is rather
+          # brittle, so it is difficult (if not impossible) to get mypy to succeed in
+          # this context, even when it succeeds in CI.
+          - dask
+          - distributed
+          - hypothesis
+          - matplotlib
+          - numpy==2.1.3
+          - pandas-stubs
+          - pytest
+          - types-colorama
+          - types-defusedxml
+          - types-docutils
+          - types-pexpect
+          - types-psutil
+          - types-Pygments
+          - types-python-dateutil
+          - types-pytz
+          - types-PyYAML
+          - types-setuptools
+          - typing-extensions>=4.1.0
   - repo: https://github.com/citation-file-format/cff-converter-python
     rev: ebf0b5e44d67f8beaa1cd13a0d0393ea04c6058d
     hooks:

xarray/core/groupby.py

@@ -1607,7 +1607,7 @@ def reduce_array(ar: DataArray) -> DataArray:
 
 
 # https://github.com/python/mypy/issues/9031
-class DataArrayGroupBy(  # type: ignore[misc]
+class DataArrayGroupBy(
     DataArrayGroupByBase,
     DataArrayGroupByAggregations,
     ImplementsArrayReduce,
@@ -1774,8 +1774,7 @@ 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"""