Fix dataarray drop attrs (pydata#10030)

* Fix DataArray().drop_attrs(deep=False)

* Add DataArray().drop_attrs() tests

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Apply small cosmetics

* Add support for attrs to DataArray()._replace

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove testing relict

* Fix (try) incompatible types mypy error

* Fix (2.try) incompatible types mypy error

* Update whats-new

* Fix replacing simultaneously passed variable

* Add DataArray()._replace() tests

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

doc/whats-new.rst

@@ -42,6 +42,9 @@ Bug fixes
 - Use mean of min/max years as offset in calculation of datetime64 mean
   (:issue:`10019`, :pull:`10035`).
   By `Kai Mühlbauer <https://github.com/kmuehlbauer>`_.
+- Fix DataArray().drop_attrs(deep=False) and add support for attrs to
+  DataArray()._replace(). (:issue:`10027`, :pull:`10030`). By `Jan
+  Haacker <https://github.com/j-haacker>`_.
 
 
 Documentation

xarray/core/dataarray.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import copy
 import datetime
 import warnings
 from collections.abc import (
@@ -522,6 +523,7 @@ def _replace(
         variable: Variable | None = None,
         coords=None,
         name: Hashable | None | Default = _default,
+        attrs=_default,
         indexes=None,
     ) -> Self:
         if variable is None:
@@ -532,6 +534,11 @@ def _replace(
             indexes = self._indexes
         if name is _default:
             name = self.name
+        if attrs is _default:
+            attrs = copy.copy(self.attrs)
+        else:
+            variable = variable.copy()
+            variable.attrs = attrs
         return type(self)(variable, coords, name=name, indexes=indexes, fastpath=True)
 
     def _replace_maybe_drop_dims(
@@ -7575,6 +7582,11 @@ def drop_attrs(self, *, deep: bool = True) -> Self:
         -------
         DataArray
         """
-        return (
-            self._to_temp_dataset().drop_attrs(deep=deep).pipe(self._from_temp_dataset)
-        )
+        if not deep:
+            return self._replace(attrs={})
+        else:
+            return (
+                self._to_temp_dataset()
+                .drop_attrs(deep=deep)
+                .pipe(self._from_temp_dataset)
+            )

xarray/tests/test_dataarray.py

@@ -1908,6 +1908,21 @@ def test_rename_dimension_coord_warnings(self) -> None:
             warnings.simplefilter("error")
             da.rename(x="x")
 
+    def test_replace(self) -> None:
+        # Tests the `attrs` replacement and whether it interferes with a
+        # `variable` replacement
+        da = self.mda
+        attrs1 = {"a1": "val1", "a2": 161}
+        x = np.ones((10, 20))
+        v = Variable(["x", "y"], x)
+        assert da._replace(variable=v, attrs=attrs1).attrs == attrs1
+        attrs2 = {"b1": "val2", "b2": 1312}
+        va = Variable(["x", "y"], x, attrs2)
+        # assuming passed `attrs` should prevail
+        assert da._replace(variable=va, attrs=attrs1).attrs == attrs1
+        # assuming `va.attrs` should be adopted
+        assert da._replace(variable=va).attrs == attrs2
+
     def test_init_value(self) -> None:
         expected = DataArray(
             np.full((3, 4), 3), dims=["x", "y"], coords=[range(3), range(4)]
@@ -2991,8 +3006,11 @@ def test_assign_attrs(self) -> None:
 
     def test_drop_attrs(self) -> None:
         # Mostly tested in test_dataset.py, but adding a very small test here
-        da = DataArray([], attrs=dict(a=1, b=2))
+        coord_ = DataArray([], attrs=dict(d=3, e=4))
+        da = DataArray([], attrs=dict(a=1, b=2)).assign_coords(dict(coord_=coord_))
         assert da.drop_attrs().attrs == {}
+        assert da.drop_attrs().coord_.attrs == {}
+        assert da.drop_attrs(deep=False).coord_.attrs == dict(d=3, e=4)
 
     @pytest.mark.parametrize(
         "func", [lambda x: x.clip(0, 1), lambda x: np.float64(1.0) * x, np.abs, abs]