class Shu(object):

    def __init__(self,ss):

        self.ss = ss

    def __str__(self):

        return '(%s: %s)' % (self.name, self.score)

    __repr__ = __str__

    def __cmp__(self, s):

        print ('func __cmp__ work')

        if self.ss < s.ss:

            return -1

        elif self.ss > s.ss:

            return 1

        else:

            return 0

a=Shu(3)

b=Shu(2)

c=a>b#运行a.__cmp__(b),c为True

d=cmp(a,b)#运行a.__cmp__(b),d为1，注意d与上面c类型不同，cmp返回的是0，-1,1