The name property is marked as protected. This was added in TypeScript 1.3 and is now firmly established. The makeSound method is marked as abstract, as is the class. You cannot directly instantiate an Animal now, because it is abstract. This is part of TypeScript 1.6, which is now officially live. abstract class Animal { … Read more
Before abc was introduced you would see this frequently. class Base(object): def go(self): raise NotImplementedError(“Please Implement this method”) class Specialized(Base): def go(self): print “Consider me implemented”
The truth is: data classes do not play too well with inheritance. We are considering prohibiting or severely restricting inheritance of data classes. For example, it’s known that there’s no way to implement equals() correctly in a hierarchy on non-abstract classes. So, all I can offer: don’t use inheritance with data classes.
Use the abc module to create abstract classes. Use the abstractmethod decorator to declare a method abstract, and declare a class abstract using one of three ways, depending upon your Python version. In Python 3.4 and above, you can inherit from ABC. In earlier versions of Python, you need to specify your class’s metaclass as … Read more
Here, i’m creating instance of my class No, you are not creating the instance of your abstract class here. Rather you are creating an instance of an anonymous subclass of your abstract class. And then you are invoking the method on your abstract class reference pointing to subclass object. This behaviour is clearly listed in … Read more
An abstract function cannot have functionality. You’re basically saying, any child class MUST give their own version of this method, however it’s too general to even try to implement in the parent class. A virtual function, is basically saying look, here’s the functionality that may or may not be good enough for the child class. … Read more