Method test_set_xindex

xarray/tests/test_dataset.py:4024–4066

(self)

            ds.reorder_levels(x=["level_1", "level_2"])

    def test_set_xindex(self) -> None:
        ds = Dataset(
            coords={"foo": ("x", ["a", "a", "b", "b"]), "bar": ("x", [0, 1, 2, 3])}
        )

        actual = ds.set_xindex("foo")
        expected = ds.set_index(x="foo").rename_vars(x="foo")
        assert_identical(actual, expected, check_default_indexes=False)

        actual_mindex = ds.set_xindex(["foo", "bar"])
        expected_mindex = ds.set_index(x=["foo", "bar"])
        assert_identical(actual_mindex, expected_mindex)

        class NotAnIndex: ...

        with pytest.raises(TypeError, match=r".*not a subclass of xarray.Index"):
            ds.set_xindex("foo", NotAnIndex)  # type: ignore[arg-type]

        with pytest.raises(ValueError, match="those variables don't exist"):
            ds.set_xindex("not_a_coordinate", PandasIndex)

        ds["data_var"] = ("x", [1, 2, 3, 4])

        with pytest.raises(ValueError, match="those variables are data variables"):
            ds.set_xindex("data_var", PandasIndex)

        ds = Dataset(coords={"x": ("x", [0, 1, 2, 3])})

        # With drop_existing=True, it should succeed
        result = ds.set_xindex("x", PandasIndex)
        assert "x" in result.xindexes
        assert isinstance(result.xindexes["x"], PandasIndex)

        class CustomIndex(PandasIndex):
            pass

        result_custom = ds.set_xindex("x", CustomIndex)
        assert "x" in result_custom.xindexes
        assert isinstance(result_custom.xindexes["x"], CustomIndex)

        # Verify the result is equivalent to drop_indexes + set_xindex
        expected = ds.drop_indexes("x").set_xindex("x", CustomIndex)
        assert_identical(result_custom, expected)

    def test_set_xindex_options(self) -> None:
        ds = Dataset(coords={"foo": ("x", ["a", "a", "b", "b"])})