-NA values are present the result will be NA.

        Returns
        -------
        Series or DataFrame
            Last non-null of values within each group.

        See Also
        --------
        DataFrame.groupby : Apply a function groupby to each row or column of a
            DataFrame.
        pandas.core.groupby.DataFrameGroupBy.first : Compute the first non-null entry
            of each column.
        pandas.core.groupby.DataFrameGroupBy.nth : Take the nth row from each group.

        Examples
        --------
        >>> df = pd.DataFrame(dict(A=[1, 1, 3], B=[5, None, 6], C=[1, 2, 3]))
        >>> df.groupby("A").last()
             B  C
        A
        1  5.0  2
        3  6.0  3
        r