Use ._replace for half the method

xarray/core/dataset.py

@@ -10344,12 +10344,13 @@ def drop_attrs(self) -> Self:
         Removes all attributes from the Dataset and its variables.
         """
         # Remove attributes from the dataset
-        self = self.copy()
-
-        self.attrs = {}
+        self = self._replace(attrs={})
 
         # Remove attributes from each variable in the dataset
         for var in self.variables:
+            # variables don't have a `._replace` method, so we copy and then remove. If
+            # we added a `._replace` method, we could use that instead.
+            self[var] = self[var].copy()
             self[var].attrs = {}
 
         return self

xarray/tests/test_dataset.py

@@ -4369,7 +4369,7 @@ def test_drop_attrs(self) -> None:
         # Example with variables and coords with attrs, check they're dropped too
         var = Variable("x", [1, 2, 3], attrs=dict(x=1, y=2))
         idx = IndexVariable("y", [1, 2, 3], attrs=dict(c=1, d=2))
-        ds = Dataset(dict(x=var), coords=dict(y=idx)).assign_attrs(a=1, b=2)
+        ds = Dataset(dict(var1=var), coords=dict(y=idx)).assign_attrs(a=1, b=2)
         assert ds.coords["y"].attrs != {}
 
         original = ds.copy(deep=True)
@@ -4378,6 +4378,8 @@ def test_drop_attrs(self) -> None:
         assert result.attrs == {}
         assert result["x"].attrs == {}
         assert result["y"].attrs == {}
+        assert list(result.data_vars) == list(ds.data_vars)
+        assert list(result.coords) == list(ds.coords)
 
         # Doesn't change original
         assert_identical(ds, original)