从派生类对象python调用基类的方法

Question

I have two class and methods having same name .I have the object of derived class. When i call the method (foo) from derived class object it should call the base class method.

class A:
    def foo(self):
        print "A Foo"

class B(A):
    def foo(self):
        print "B Foo"

b = B()
b.foo() # "B Foo"

After doing some search i got some solution as below and not sure whether it is proper way of doing it or not

a = A()
b.__class__.__bases__[0].foo(a) # A Foo

Is there any better way of doing it.

Answer 1

If you're using Python 3, use super :

class A:
    def talk(self):
        print('Hi from A-land!')

class B(A):
    def talk(self):
        print('Hello from B-land!')

    def pass_message(self):
        super().talk()

b = B()
b.talk()
b.pass_message()

Output:

Hello from B-land!
Hi from A-land!

You can do the same thing in Python 2 if you inherit from object and specify the parameters of super :

class B(A):
    def talk(self):
        print('Hello from B-land!')

    def pass_message(self):
        super(B, self).talk()

b = B()
b.talk()
b.pass_message()

Output:

Hello from B-land!
Hi from A-land!

You can also call the method as if it were a free function:

A.talk(b)
B.talk(b)  # the same as b.talk()

Output:

Hi from A-land!
Hello from B-land!

Answer 2

When you call the method (foo) from derived class object, it won't call the base class method, because you're overriding it. You can use another method name for your base class or derived class to solve the interference.