def lpol_sdiff(s):
    '''return coefficients for seasonal difference (1-L^s)

    just a trivial convenience function

    Parameters
    ----------
    s : int
        number of periods in season

    Returns
    -------
    sdiff : list, length s+1

    '''
    return [1] + [0]*(s-1) + [-1]
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/tsa/arima_process.py/lpol_sdiff/original