def lpol_sdiff(s):
 return (([1] + ([0] * (s - 1))) + [(-1)])

def lpol_sdiff ( s ) : return ( ( [ 1 ] + ( [ 0 ] * ( s - 1 ) ) ) + [ ( - 1 ) ] )
return coefficients for seasonal difference just a trivial convenience function parameters s : int number of periods in season returns sdiff : list .