self，列表推导，分片，集合

class AthleteList(list):        def __init__(self, a_name, a_dob=None, atimes=[]):        list.__init__([])        self.name = a_name        self.dob = a_dob        self.extend(atimes)        def top3(self):#列表推导和分片        return(sorted(set([sanitize(t) for t in self]))[0:3])