Class Inheritance in Object-Oriented Programs

Programming Paradigm Concepts

Eleanor Thomas

Senior Data Analytics Engineer

Class inheritance in object-oriented programming

Class inheritance: when one class "inherits" methods and attributes from another, parent class
Example:
- Poodle class inherits from Dog (and has curly hair)
- Dog class inherits from Pet (and "barks")
- Pet class inherits from Animal
No limit to the number of layers of inheritance, but more is not always better

Group of pets

Class inheritance example

class Dog():
    def __init__(self, name):
        self.name = name
    def bark(self):
        print("Arf!")

lacy = Dog("Lacy")
lacy.bark()

class Pet():
    def __init__(self, name):
        self.name = name


class Dog(Pet):
    def bark(self):
        print("Arf!")


lacy = Dog("Lacy")
lacy.bark()

Class inheritance example continued

class Cat(Pet):
    def meow(self):
        print("Meow!")


class Horse(Pet):
    def neigh(self):
        print("Neigh!")

fluffy = Cat("Fluffy")
fluffy.meow()

Meow!

midnight = Horse("Midnight")
midnight.neigh()

Neigh!

All of the following produce Errors!

fluffy.neigh()

fluffy.bark()

midnight.meow()

Let's practice!

Programming Paradigm Concepts