如何检测方法重载在python中的子类？ [英] How to detect method overloading in subclasses in python?

问题描述

我有一个类是许多其他类的超类。我想知道（在 init （）我的超类，如果子类覆盖了一个特定的方法。

I have a class that is a super-class to many other classes. I would like to know (in the init() of my super-class if the subclass has overridden a specific method.

但是结果是错误的：

class Super:
   def __init__(self):
      if self.method == Super.method:
         print 'same'
      else:
         print 'different'

   @classmethod
   def method(cls):
      pass

class Sub1(Super):
   def method(self):
      print 'hi'

class Sub2(Super):
   pass

Super() # should be same
Sub1() # should be different
Sub2() # should be same

>>> same
>>> different
>>> different

有一个超类可以知道子类是否重写了一个方法？

Is there any way for a super-class to know if a sub-class has overridden a method?

推荐答案

你可以使用自己的装饰器，但这是一个诀窍，只能在你控制实现的类上。

You can use your own decorator. But this is a trick and will only work on classes where you control the implementation.

def override(method):
  method.is_overridden = True
  return method

class Super:
   def __init__(self):
      if hasattr(self.method, 'is_overridden'):
         print 'different'
      else:
         print 'same'
   @classmethod
   def method(cls):
      pass

class Sub1(Super):
   @override
   def method(self):
      print 'hi'

class Sub2(Super):
   pass

Super() # should be same
Sub1() # should be different
Sub2() # should be same

>>> same
>>> different
>>> same

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