Using attributes from the derived class in the base class

Question

In the project I'm working on, we have a hierarchy of classes with each class defining a get_text() method.

class Base:
    def get_text(self):
        raise NotImplementedError

class Derived1(Base):
    def get_text(self):
        return "Text from Derived1"

class Derived2(Base):
    def get_text(self):
        return "Text from Derived2"

obj1 = Derived1()
print(obj1.get_text())
==> 'Text from Derived1'

obj2 = Derived2()
print(obj2.get_text())
==> 'Text from Derived2'

This way, the programmer can call obj.get_text() and get the text from the class obj is pointing to.

Now I want to refactor the method to be just an attribute (called TEXT ). I want to keep the original methods for backward compatibility, though. Is there a way to do it in the base class only?

class Base:
    def get_text(self):
        """
        Keep backward compatibility.
        """
        return TEXT  # What should be here?

class Derived1(Base):
    TEXT = "Text from Derived1"

class Derived2(Base):
    TEXT = "Text from Derived2"

obj1 = Derived1()
print(obj1.TEXT)

# Non-refactored code
obj2 = Derived2()
print(obj2.get_text())
==> NameError: name 'TEXT' is not defined

Coming from C++, I'm used to having a pointer to the base class invoke a method from the derived class using C++ virtual method dispatching. Is something similar possible in Python?

Answer 1

To answer my own question (thanks to the commenters:) both following ways work:

return self.__class__.TEXT

Here, self.__class__ points either to Derived1 or to Derived2 class objects, which have access to TEXT .

return self.TEXT

makes this one step shorter, as the attribute resolution algorithm accesses class attributes automatically.