Part 5.2Inheritance in Python

The concept of inheritance is focused entirely on code reuse and maintainability of code.

Inheritance is a fundamental part of object-oriented design that allows one class (the subclass) to inherit attributes and methods of another class (the superclass).

Inheritance in Python

A cat is an animal, so we can define an Animal superclass as shown below:

class Animal:
  # An animal class
  type = ""
  name = ""

  def __init__(self, type, name):
    self.type = type
    self.name = name

  def act(self):
    print("Doing something")

  def getName(self):
    return self.name

Now, we can define a Cat class for our cat:

class Cat (Animal):
  # A cat class
  name = ""

  def __init__(self, name):
    self.type = "Cat"
    self.name = name

  def act(self):
    print("Meow")

Now in the same program, instantiating a new cat and using the act method on the newly instantiated cat, we should get the word Meow on the screen.

c = Cat("Gismo")
c.act()
print(c.getName())

This is simply overwriting the act method defined in the Animal superclass with its own derivation of it and then utilising the getName method from the superclass to get the name property of the instance.

class Animal:
    def act(self):
        print("Doing something")

class Dog(Animal):
    def act(self):
        print("Woof")

d = Dog()
d.act()
    

class Animal:
    def act(self):
        print("Doing something")

class Bird(Animal):
    def act(self):
        print("Chirp")

b = Bird()
b.act()