Python Practice Lesson 9 of 22

Classes and inheritance

__init__(self, ...) is Python's constructor - it runs automatically when you create an instance, and it's where you set the instance's own data with self.attribute = value. Methods defined in the class body are shared by every instance instead of copied onto each one; self is how a method reaches back into the specific instance it was called on.

class Dog(Animal): builds a subclass - Dog gets every method Animal has for free, and only needs to define what's different. Overriding a method - writing a same-named method in the subclass - replaces the parent's version for instances of the subclass, without touching how Animal itself behaves. super().__init__(...) lets a subclass reuse the parent's constructor instead of duplicating it, though this lesson's Dog doesn't need its own __init__ at all - it can just inherit Animal's.

Your task: write class Animal with __init__(self, name) storing self.name, and a method speak(self) returning f"{self.name} makes a sound". Then write class Dog, extending Animal, that overrides speak() to return f"{self.name} barks" instead.

You'll practice:

Writing __init__ and a method on a class
Subclassing with inheritance and overriding one method

# Write class Animal: __init__(self, name) stores self.name;
# speak(self) returns f"{self.name} makes a sound".
class Animal:
    pass

# Write class Dog(Animal): override speak() to return f"{self.name} barks".
class Dog(Animal):
    pass