Builds TripleOrbitPopulation from DataFrame

        ``DataFrame`` objects must be of appropriate form to pass
        to :func:`OrbitPopulation.from_df`.

        :param df_long, df_short:
            :class:`pandas.DataFrame` objects to pass to
            :func:`OrbitPopulation.from_df`.

def from_df(cls, df_long, df_short):
        """
        Builds TripleOrbitPopulation from DataFrame

        ``DataFrame`` objects must be of appropriate form to pass
        to :func:`OrbitPopulation.from_df`.

        :param df_long, df_short:
            :class:`pandas.DataFrame` objects to pass to
            :func:`OrbitPopulation.from_df`.

        """
        pop = cls(1,1,1,1,1) #dummy population
        pop.orbpop_long = OrbitPopulation.from_df(df_long)
        pop.orbpop_short = OrbitPopulation.from_df(df_short)
        return pop