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Consider the following hierarchy of classes:

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)

As written, this code leads to an infinite loop when using the Arrogant Professor class.

Change the definition of ArrogantProfessor so that the following behavior is achieved:

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

my solution to this is:

But the checker gives only half marks for this solution.What is the mistake that I am making and what are the test cases on which this code fails? (I am new to python and learned about classes some time ago)

Consider the following hierarchy of classes:

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)

As written, this code leads to an infinite loop when using the Arrogant Professor class.

Change the definition of ArrogantProfessor so that the following behavior is achieved:

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

My solution to this is:

But the checker gives only half marks for this solution. What is the mistake that I am making and what are the test cases on which this code fails? (I am new to python and learned about classes some time ago.)

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

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