@derived_from(pd.Series)
    def append(self, other):
        # because DataFrame.append will override the method,
        # wrap by pd.Series.append docstring

        if isinstance(other, (list, dict)):
            msg = "append doesn't support list or dict input"
            raise NotImplementedError(msg)

        if not isinstance(other, _Frame):
            from .io import from_pandas
            other = from_pandas(other, 1)

        from .multi import _append
        if self.known_divisions and other.known_divisions:
            if other.divisions[0] < self.divisions[-1]:
                divisions = self.divisions[:-1] + other.divisions
                return _append(self, other, divisions)
            else:
                msg = ("Unable to append two dataframes to each other with known "
                       "divisions if those divisions are not ordered. "
                       "The divisions/index of the second dataframe must be "
                       "greater than the divisions/index of the first dataframe.")
                raise ValueError(msg)
        else:
            divisions = [None] * (self.npartitions + other.npartitions + 1)
            return _append(self, other, divisions)
dataset/ETHPy150Open dask/dask/dask/dataframe/core.py/_Frame.append/swapped operands of `<`