问题详述：

代码如下:

class Super:  
    def method(self):  
        print "Super's method"  
  
class Sub(Super):  
    def method(self):  
        print "Sub's method"  
        Super.method()  
        print "Over..."  
  
S = Sub()  
S.method()

执行上面一段代码，错误如下:

代码如下:

>>>   
Sub's method  
  
Traceback (most recent call last):  
  File "D:\Learn\Python\test.py", line 12, in <module>  
    S.method()  
  File "D:\Learn\Python\test.py", line 8, in method  
    Super.method()  
TypeError: unbound method method() must be called with Super instance as first argument (got nothing instead)

详细解答：

【错误分析】Python中调用类的方法，必须与实例绑定，或者调用自身.

代码如下:

ClassName.method(x, 'Parm')
ClassName.method(self)

所以上面代码，要调用Super类的话，只需要加个self参数即可。

代码如下:

class Super:  
    def method(self):  
        print "Super's method"  
  
class Sub(Super):  
    def method(self):  
        print "Sub's method"  
        Super.method(self)  
        print "Over..."  
  
S = Sub()  
S.method()

#输出结果

>>>   
Sub's method  
Super's method  
Over...