def describe_constant_1d(series):
    """Compute summary statistics of a constant (`S_TYPE_CONST`) variable (a Series).

    Parameters
    ----------
    series : Series
        The variable to describe.

    Returns
    -------
    Series
        The description of the variable as a Series with index being stats keys.
    """
    return pd.Series([base.S_TYPE_CONST], index=['type'], name=series.name)