源码如下：
#!/usr/bin/env python class Bird(): def __init__(self): self.hungry = True def eat(self): if self.hungry: print ‘Aaaah...‘ self.hungry = False else: print ‘No, Thanks!‘ class SongBird(Bird): def __init__(self): super(SongBird, self).__init__() # Bird.__init__(self) self.sound = ‘Squawk!‘ def sing(self): print self.sound
错误信息如下：
>>> from Bird import Bird, SongBird >>> b = Bird() >>> b.eat() Aaaah... >>> b.eat() No, Thanks! >>> sb = SongBird() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "Bird.py", line 17, in __init__ super(SongBird, self).__init__() TypeError: must be type, not classobj
错误原因：
使用super初始化父类只对父类为新风格（new-style）的生效，对旧风格的不生效。
解决方式1：
#!/usr/bin/env python # 使用new-style class Bird(object): def __init__(self): self.hungry = True def eat(self): if self.hungry: print ‘Aaaah...‘ self.hungry = False else: print ‘No, Thanks!‘ class SongBird(Bird): def __init__(self): super(SongBird, self).__init__() self.sound = ‘Squawk!‘ def sing(self): print self.sound
解决方法2：
#!/usr/bin/env python __metaclass__ = type class Bird: def __init__(self): self.hungry = True def eat(self): if self.hungry: print ‘Aaaah...‘ self.hungry = False else: print ‘No, Thanks!‘ class SongBird(Bird): def __init__(self): super(SongBird, self).__init__() self.sound = ‘Squawk!‘ def sing(self): print self.sound
解决方法3（使用old-style）：
#!/usr/bin/env python class Bird(): def __init__(self): self.hungry = True def eat(self): if self.hungry: print ‘Aaaah...‘ self.hungry = False else: print ‘No, Thanks!‘ class SongBird(Bird): def __init__(self): # 不使用super进行初始化 Bird.__init__(self) self.sound = ‘Squawk!‘ def sing(self): print self.sound