Function as_variable

xarray/core/variable.py:98–189

Convert an object into a Variable. Parameters ---------- obj : object Object to convert into a Variable. - If the object is already a Variable, return a shallow copy. - Otherwise, if the object has 'dims' and 'data' attributes, convert it into a new Va

(
    obj: T_DuckArray | Any, name=None, auto_convert: bool = True
)

def as_variable(
    obj: T_DuckArray | Any, name=None, auto_convert: bool = True
) -> Variable | IndexVariable:
    """Convert an object into a Variable.

    Parameters
    ----------
    obj : object
        Object to convert into a Variable.

        - If the object is already a Variable, return a shallow copy.
        - Otherwise, if the object has 'dims' and 'data' attributes, convert
          it into a new Variable.
        - If all else fails, attempt to convert the object into a Variable by
          unpacking it into the arguments for creating a new Variable.
    name : str, optional
        If provided:

        - `obj` can be a 1D array, which is assumed to label coordinate values
          along a dimension of this given name.
        - Variables with name matching one of their dimensions are converted
          into `IndexVariable` objects.
    auto_convert : bool, optional
        For internal use only! If True, convert a "dimension" variable into
        an IndexVariable object (deprecated).

    Returns
    -------
    var : Variable
        The newly created variable.

    """
    from xarray.core.dataarray import DataArray

    # TODO: consider extending this method to automatically handle Iris and
    if isinstance(obj, DataArray):
        # extract the primary Variable from DataArrays
        obj = obj.variable

    if isinstance(obj, Variable):
        obj = obj.copy(deep=False)
    elif isinstance(obj, tuple):
        try:
            dims_, data_, *attrs = obj
        except ValueError as err:
            raise ValueError(
                f"Tuple {obj} is not in the form (dims, data[, attrs])"
            ) from err

        if isinstance(data_, DataArray):
            raise TypeError(
                f"Variable {name!r}: Using a DataArray object to construct a variable is"
                " ambiguous, please extract the data using the .data property."
            )
        try:
            obj = Variable(dims_, data_, *attrs)
        except (TypeError, ValueError) as error:
            raise error.__class__(