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Description: PR 11020 - bugfix from upstream
Bug-Origin: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1123151
Forwarded: not-needed
Last-Updated: 2026-01-06
Index: python-xarray-2026.01.0/doc/whats-new.rst
===================================================================
--- python-xarray-2026.01.0.orig/doc/whats-new.rst
+++ python-xarray-2026.01.0/doc/whats-new.rst
@@ -140,6 +140,10 @@ New Features
Bug Fixes
~~~~~~~~~
+- :py:meth:`Dataset.map` now merges attrs from the function result and the original
+ using the ``drop_conflicts`` strategy when ``keep_attrs=True``, preserving attrs
+ set by the function (:issue:`11019`, :pull:`11020`).
+ By `Maximilian Roos <https://github.com/max-sixty>`_.
- When assigning an indexed coordinate to a data variable or coordinate, coerce it from
``IndexVariable`` to ``Variable`` (:issue:`9859`, :issue:`10829`, :pull:`10909`).
By `Julia Signell <https://github.com/jsignell>`_.
Index: python-xarray-2026.01.0/xarray/computation/weighted.py
===================================================================
--- python-xarray-2026.01.0.orig/xarray/computation/weighted.py
+++ python-xarray-2026.01.0/xarray/computation/weighted.py
@@ -544,14 +544,28 @@ class DataArrayWeighted(Weighted["DataAr
dataset = self.obj._to_temp_dataset()
dataset = dataset.map(func, dim=dim, **kwargs)
- return self.obj._from_temp_dataset(dataset)
+ result = self.obj._from_temp_dataset(dataset)
+ # Clear attrs when keep_attrs is explicitly False
+ # (weighted operations can propagate attrs from weights through internal computations)
+ if kwargs.get("keep_attrs") is False:
+ result.attrs = {}
+
+ return result
class DatasetWeighted(Weighted["Dataset"]):
def _implementation(self, func, dim, **kwargs) -> Dataset:
self._check_dim(dim)
- return self.obj.map(func, dim=dim, **kwargs)
+ result = self.obj.map(func, dim=dim, **kwargs)
+
+ # Clear attrs when keep_attrs is explicitly False
+ # (weighted operations can propagate attrs from weights through internal computations)
+ if kwargs.get("keep_attrs") is False:
+ result.attrs = {}
+ for var in result.data_vars.values():
+ var.attrs = {}
+ return result
def _inject_docstring(cls, cls_name):
cls.sum_of_weights.__doc__ = _SUM_OF_WEIGHTS_DOCSTRING.format(cls=cls_name)
Index: python-xarray-2026.01.0/xarray/core/dataset.py
===================================================================
--- python-xarray-2026.01.0.orig/xarray/core/dataset.py
+++ python-xarray-2026.01.0/xarray/core/dataset.py
@@ -6914,8 +6914,11 @@ class Dataset(
DataArray.
keep_attrs : bool or None, optional
If True, both the dataset's and variables' attributes (`attrs`) will be
- copied from the original objects to the new ones. If False, the new dataset
- and variables will be returned without copying the attributes.
+ combined from the original objects and the function results using the
+ ``drop_conflicts`` strategy: matching attrs are kept, conflicting attrs
+ are dropped. If False, the new dataset and variables will have only
+ the attributes set by the function.
+
args : iterable, optional
Positional arguments passed on to `func`.
**kwargs : Any
@@ -6964,16 +6967,19 @@ class Dataset(
coords = Coordinates._construct_direct(coords=coord_vars, indexes=indexes)
if keep_attrs:
+ # Merge attrs from function result and original, dropping conflicts
+ from xarray.structure.merge import merge_attrs
+
for k, v in variables.items():
- v._copy_attrs_from(self.data_vars[k])
+ v.attrs = merge_attrs(
+ [v.attrs, self.data_vars[k].attrs], "drop_conflicts"
+ )
for k, v in coords.items():
if k in self.coords:
- v._copy_attrs_from(self.coords[k])
- else:
- for v in variables.values():
- v.attrs = {}
- for v in coords.values():
- v.attrs = {}
+ v.attrs = merge_attrs(
+ [v.attrs, self.coords[k].attrs], "drop_conflicts"
+ )
+ # When keep_attrs=False, leave attrs as the function returned them
attrs = self.attrs if keep_attrs else None
return type(self)(variables, coords=coords, attrs=attrs)
Index: python-xarray-2026.01.0/xarray/core/datatree.py
===================================================================
--- python-xarray-2026.01.0.orig/xarray/core/datatree.py
+++ python-xarray-2026.01.0/xarray/core/datatree.py
@@ -397,8 +397,10 @@ class DatasetView(Dataset):
DataArray.
keep_attrs : bool | None, optional
If True, both the dataset's and variables' attributes (`attrs`) will be
- copied from the original objects to the new ones. If False, the new dataset
- and variables will be returned without copying the attributes.
+ combined from the original objects and the function results using the
+ ``drop_conflicts`` strategy: matching attrs are kept, conflicting attrs
+ are dropped. If False, the new dataset and variables will have only
+ the attributes set by the function.
args : iterable, optional
Positional arguments passed on to `func`.
**kwargs : Any
@@ -438,8 +440,13 @@ class DatasetView(Dataset):
for k, v in self.data_vars.items()
}
if keep_attrs:
+ # Merge attrs from function result and original, dropping conflicts
+ from xarray.structure.merge import merge_attrs
+
for k, v in variables.items():
- v._copy_attrs_from(self.data_vars[k])
+ v.attrs = merge_attrs(
+ [v.attrs, self.data_vars[k].attrs], "drop_conflicts"
+ )
attrs = self.attrs if keep_attrs else None
# return type(self)(variables, attrs=attrs)
return Dataset(variables, attrs=attrs)
Index: python-xarray-2026.01.0/xarray/tests/test_dataset.py
===================================================================
--- python-xarray-2026.01.0.orig/xarray/tests/test_dataset.py
+++ python-xarray-2026.01.0/xarray/tests/test_dataset.py
@@ -6509,6 +6509,36 @@ class TestDataset:
expected = xr.Dataset({"foo": 42, "bar": ("y", [4, 5])})
assert_identical(result, expected)
+ def test_map_preserves_function_attrs(self) -> None:
+ # Regression test for GH11019
+ # Attrs added by function should be preserved in result
+ ds = xr.Dataset({"test": ("x", [1, 2, 3], {"original": "value"})})
+
+ def add_attr(da):
+ return da.assign_attrs(new_attr="foobar")
+
+ # With keep_attrs=True: merge using drop_conflicts (no conflict here)
+ result = ds.map(add_attr, keep_attrs=True)
+ assert result["test"].attrs == {"original": "value", "new_attr": "foobar"}
+
+ # With keep_attrs=False: function's attrs preserved
+ result = ds.map(add_attr, keep_attrs=False)
+ assert result["test"].attrs == {"original": "value", "new_attr": "foobar"}
+
+ # When function modifies existing attr with keep_attrs=True, conflict is dropped
+ def modify_attr(da):
+ return da.assign_attrs(original="modified", extra="added")
+
+ result = ds.map(modify_attr, keep_attrs=True)
+ assert result["test"].attrs == {
+ "extra": "added"
+ } # "original" dropped due to conflict
+
+ # When function modifies existing attr with keep_attrs=False, function wins
+ result = ds.map(modify_attr, keep_attrs=False)
+ assert result["test"].attrs == {"original": "modified", "extra": "added"}
+
+
def test_apply_pending_deprecated_map(self) -> None:
data = create_test_data()
data.attrs["foo"] = "bar"
|
