How do I call the parent method of a class inside completely non-related class?

问题

I want to use the superclass to call the parent method of a class while using a different class.

Class AI():
...

 for i in self.initial_computer_group:
             if i.rect.x == current_coords[0] and i.rect. y== current_coords[1]:
                 i.move(coords_to_move[0], coords_to_move[1])

i.move() calls a method from an inherited class, when I want the original method from the parent class.

self.initial_computer_group contains a list of objects which are completely unrelated to the AI class.

I know I need to somehow get the class name of the current object i references to, but then I don't know what to use as the second argument in super() as i can't use self, since it's unrelated to AI.

So how do I use super() when I'm in a completely different class to what super is meant to call?

Note: I want to call the parent method as it speeds everything up. I only designed the inherited method to ensure the human isn't breaking the rules in this chess game.

EDIT: I found a solution by changing the name of the inherited method to something else, but I was wondering whether there's still a special way to invoke super() to solve the problem

回答1:

It sounds like you want to call a specific class's method, no matter what the inheritance graph looks like (and in particular, even if that method happens to be overridden twice). In that case, you don't want super. Instead, call the class's method directly. For example, assuming the version you want is in the Foo class:

Foo.move(i, coords_to_move[0], coords_to_move[1])

回答2:

As it's hard to read code in comments, here's a simple example:

class BaseClass():
    def func(self):
        print("Here in BaseClass.")


class InheritedClass(BaseClass):
    def func(self):
        print("Here in InheritedClass.")


def func(instance):
    super(InheritedClass, instance).func()

In use:

>>> func(InheritedClass())
Here in BaseClass.

But this clearly makes your code less flexible (as the instance argument must be an InheritedClass instance), and should generally be avoided.

回答3:

Given some inheritance hierarchy:

class Super:                 # descends from object 
    def func():
        return 'Super calling'

class Base(Super):
    def func():
        return 'Base calling'

class Sub(Base):
    def func():
        return 'Sub calling'

You can get the resolution hierarchy with the __mro__ attribute:

>>> s=Sub()
>>> s.__class__.__mro__
(<class '__main__.Sub'>, <class '__main__.Base'>, <class '__main__.Super'>, <class 'object'>)

Then you can pick among those by index:

>>> s.__class__.__mro__[-2]
<class '__main__.Super'>
>>> s.__class__.__mro__[-2].func()
Super calling

You can get a specific name by matching against the __name__ attribute:

def by_name(inst, tgt):
    for i, c in enumerate(inst.__class__.__mro__):
        if c.__name__==tgt:
            return i

    return -1

Then if you want to call the parent class of an unrelated class, just use one of these methods on an instance of the descendant class with the method of interest.

Of course the simplest answer is if you know the class and method you want, just call it directly:

>>> Super.func()
Super calling
>>> Base.func()  
Base calling

If you need to go several levels up (or an unknown number of levels up) to find the method, Python will do that for you:

class Super:
    def func():
        return 'Super calling'

class Base(Super):
    pass

class Sub(Base):
    pass    

>>> Sub.func()
Super calling

来源：https://stackoverflow.com/questions/25118472/how-do-i-call-the-parent-method-of-a-class-inside-completely-non-related-class

标签

python

python-3.x

superclass

super