python中的类继承

Question

我正在解决这个问题:

考虑以下类的层次结构:

class Person(object):     
    def __init__(self, name):         
        self.name = name     
    def say(self, stuff):         
        return self.name + ' says: ' + stuff     
    def __str__(self):         
        return self.name  

class Lecturer(Person):     
    def lecture(self, stuff):         
        return 'I believe that ' + Person.say(self, stuff)  

class Professor(Lecturer): 
    def say(self, stuff): 
        return self.name + ' says: ' + self.lecture(stuff)

class ArrogantProfessor(Professor): 
    def say(self, stuff): 
        return 'It is obvious that ' + self.say(stuff)

如上所述,当使用Arrogant Professor类时,此代码会导致无限循环.

更改ArrogantProfessor的定义,以便实现以下行为:

e = Person('eric') 
le = Lecturer('eric') 
pe = Professor('eric') 
ae = ArrogantProfessor('eric')

e.say('the sky is blue')              #returns   eric says: the sky is blue

le.say('the sky is blue')             #returns   eric says: the sky is blue

le.lecture('the sky is blue')         #returns   believe that eric says: the sky is blue

pe.say('the sky is blue')             #returns   eric says: I believe that eric says: the sky is blue

pe.lecture('the sky is blue')     #returns   believe that eric says: the sky is blue

ae.say('the sky is blue')         #returns   eric says: It is obvious that eric says: the sky is blue

ae.lecture('the sky is blue')     #returns   It is obvious that eric says: the sky is blue

我的解决方案是:

class ArrogantProfessor(Person):
    def say(self, stuff):
        return Person.say(self, ' It is obvious that ') +  Person.say(self,stuff)
    def lecture(self, stuff):
        return 'It is obvious that  ' + Person.say(self, stuff)

但是检查器只给出了这个解决方案的一半标记.我犯的错误是什么,以及此代码失败的测试用例是什么？(我是python的新手,不久前就开始学习类.)

Answer 1

您可能应该使用super()而不是硬连接类Person:

class ArrogantProfessor(Person):
    def say(self, stuff):
        return super(ArrogantProfessor, self).say(self.lecture(stuff))
    def lecture(self, stuff):
        return 'It is obvious that ' + super(ArrogantProfessor, self).say(stuff)