Class DatasetCoordinates

xarray/core/coordinates.py:876–979

Dictionary like container for Dataset coordinates (variables + indexes). This collection can be passed directly to the :py:class:`~xarray.Dataset` and :py:class:`~xarray.DataArray` constructors via their `coords` argument. This will add both the coordinates variables and their index.

class DatasetCoordinates(Coordinates):
    """Dictionary like container for Dataset coordinates (variables + indexes).

    This collection can be passed directly to the :py:class:`~xarray.Dataset`
    and :py:class:`~xarray.DataArray` constructors via their `coords` argument.
    This will add both the coordinates variables and their index.
    """

    _data: Dataset

    __slots__ = ("_data",)

    def __init__(self, dataset: Dataset):
        self._data = dataset

    @property
    def _names(self) -> set[Hashable]:
        return self._data._coord_names

    @property
    def dims(self) -> Frozen[Hashable, int]:
        # deliberately display all dims, not just those on coordinate variables - see https://github.com/pydata/xarray/issues/9466
        return self._data.dims

    @property
    def dtypes(self) -> Frozen[Hashable, np.dtype]:
        """Mapping from coordinate names to dtypes.

        Cannot be modified directly, but is updated when adding new variables.

        See Also
        --------
        Dataset.dtypes
        """
        return Frozen(
            {
                n: v.dtype
                for n, v in self._data._variables.items()
                if n in self._data._coord_names
            }
        )

    @property
    def variables(self) -> Mapping[Hashable, Variable]:
        return Frozen(
            {k: v for k, v in self._data.variables.items() if k in self._names}
        )

    def __getitem__(self, key: Hashable) -> DataArray:
        if key in self._data.data_vars:
            raise KeyError(key)
        return self._data[key]

    def to_dataset(self) -> Dataset:
        """Convert these coordinates into a new Dataset"""

        names = [name for name in self._data._variables if name in self._names]
        return self._data._copy_listed(names)