class Bird:     def __init__(self):         self.hungry = True     def eat(self):         if self.hungry:             print('Aaaaah')             self.hungry = False         else:             print('No. thanks') class SongBird(Bird):     def __init__(self):         Bird.__init__(self)         self.sound = 'squawk'     def sing(self):         print(self.sound) class SongBird(Bird):     def __init__(self):         super(SongBird, self).__init__()         self.sound = 'squawk'     def sing(self):         print(self.sound)