How to implement virtual methods in Python?

Question

I know virtual methods from PHP or Java.

How can they be implemented in Python?

Or have I to define an empty method in an abstract class and override it?

Answer 1

Actually, in version 2.6 python provides something called abstract base classes and you can explicitly set virtual methods like this:

from abc import ABCMeta
from abc import abstractmethod
...
class C:
    __metaclass__ = ABCMeta
    @abstractmethod
    def my_abstract_method(self, ...):

It works very well, provided the class does not inherit from classes that already use metaclasses.

source: http://docs.python.org/2/library/abc.html