Python-继承和方法重写

Question

I have two classes, one inheriting from the other. Let's call them Parent and Child . Both of the objects created from those classes should use function funA , which looks like below

funA():
  X = another_function()
  Y = # some value
  X.append(Y)
  # do other computations

For both classes, function funA looks almost the same, except function another_function() , which computes in a different way the list X for the Parent and differently for the Child . Of course, I know that I can override function funA in the Child class, but since this function is very long and does several operations, copy-pasting it would be a little bit a waste. On the other hand - I have to distinguish that the Parent class should use one version of another_function() and the Child class should use the second version of another_function() . Is is maybe possible to point which version of another_function (let's call them another_function_v1 and another_function_v2 ) should be used by each class or the only solution if to override the whole function funA ?

Answer 1

Your post is not quite clear but I assume funA is a method of Parent . If yes, just add some another_method method calling the right function:

class Parent(object):
    def another_method(self):
        return another_function_v1()

    def funA(self):
        X = self.another_method()
        Y = # some value
        X.append(Y)
        # do other computations

class Child(Parent):
    def another_method(self):
        return another_method_v2()

nb if funA is a classmethod you will want to make another_method a classmethod too...

Answer 2

I don't know where your another_functions come. I suppose they are normal functions, which can be imported and used

class Parent(object):
    another_function = another_function_v1
    def funA(self):
        X = self.another_function()
        Y = # some value
        X.append(Y)
        # do other computations

class Child(Parent):
    another_function = another_function_v2