remove future warned scalar get item (#433)

* remove future warned scalar get item

* fix: remove tests on single variable getter

* update release notes

Author: FabianHofmann

doc/release_notes.rst

@@ -14,6 +14,9 @@ Version 0.5.6
 
 * With this release, the package support for Python 3.9 was dropped and support for Python 3.10 was officially added.
 
+* The selection of a single item in `__getitem__` now returns a `Variable` instead of a `ScalarVariable`.
+
+
 Version 0.5.5
 --------------
 

linopy/variables.py

@@ -199,22 +199,9 @@ def __init__(
     def __getitem__(
         self, selector: list[int] | int | slice | tuple[int64, str_]
     ) -> Variable | ScalarVariable:
-        keys = selector if isinstance(selector, tuple) else (selector,)
-        if all(map(pd.api.types.is_scalar, keys)):
-            warn(
-                "Accessing a single value with `Variable[...]` and return type "
-                "ScalarVariable is deprecated. In future, this will return a Variable."
-                "To get a ScalarVariable use `Variable.at[...]` instead.",
-                FutureWarning,
-            )
-            return self.at[keys]
-
-        else:
-            # return selected Variable
-            data = Dataset(
-                {k: self.data[k][selector] for k in self.data}, attrs=self.attrs
-            )
-            return self.__class__(data, self.model, self.name)
+        # return selected Variable
+        data = Dataset({k: self.data[k][selector] for k in self.data}, attrs=self.attrs)
+        return self.__class__(data, self.model, self.name)
 
     @property
     def attrs(self) -> dict[str, Hashable]:

test/test_variable.py

@@ -73,9 +73,7 @@ def test_wrong_variable_init(m: Model, x: linopy.Variable) -> None:
 
 
 def test_variable_getter(x: linopy.Variable, z: linopy.Variable) -> None:
-    with pytest.warns(FutureWarning):
-        assert isinstance(x[0], linopy.variables.ScalarVariable)
-        assert isinstance(z[0], linopy.variables.ScalarVariable)
+    assert isinstance(x[0], linopy.variables.Variable)
 
     assert isinstance(x.at[0], linopy.variables.ScalarVariable)