Purpose of polymorphism in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Polymorphism Purpose

What is the main purpose of polymorphism in programming?

A To allow objects of different classes to be treated as objects of a common superclass

B To increase the speed of program execution by using multiple processors

C To store multiple values in a single variable

D To prevent any changes to the data once it is set

💡 Hint

Think about how different objects can share the same interface or method names.

Polymorphism allows different classes to be accessed through the same interface, enabling flexible and reusable code.

❓ Predict Output

intermediate

Output of Polymorphism Example

What is the output of this Python code demonstrating polymorphism?

Python

class Animal:
    def sound(self):
        return "Some sound"

class Dog(Animal):
    def sound(self):
        return "Bark"

class Cat(Animal):
    def sound(self):
        return "Meow"

animals = [Dog(), Cat(), Animal()]
for animal in animals:
    print(animal.sound())

A

Some sound
Some sound
Some sound

B

Bark
Bark
Bark

C

Bark
Meow
Some sound

D

Meow
Bark
Some sound

💡 Hint

Each subclass overrides the sound method.

The Dog and Cat classes override the sound method of Animal. When called, the method of the actual object type runs.

🔧 Debug

advanced

Identify the Polymorphism Error

What error will this code produce related to polymorphism?

Python

class Bird:
    def fly(self):
        print("Flying")

class Penguin(Bird):
    pass

p = Penguin()
p.fly()

A No error, prints 'Flying'

B TypeError: Cannot call fly on Penguin

C AttributeError: 'Penguin' object has no attribute 'fly'

D NameError: Bird is not defined

💡 Hint

Check if Penguin inherits the method from Bird.

Penguin inherits from Bird, so it has the fly method. Calling p.fly() prints 'Flying' without error.

📝 Syntax

advanced

Correct Polymorphic Method Syntax

Which option correctly defines a polymorphic method area in two classes?

Python

class Shape:
    def area(self):
        pass

class Square(Shape):
    def __init__(self, side):
        self.side = side

    # Define area method here

class Circle(Shape):
    def __init__(self, radius):
        self.radius = radius

    # Define area method here

A

Square: def area(self): return self.side + self.side
Circle: def area(self): return 3.14 * self.radius

B

Square: def area(): return side * side
Circle: def area(): return 3.14 * radius ** 2

C

Square: def area(self): return side * side
Circle: def area(self): return 3.14 * radius ** 2

D

Square: def area(self): return self.side * self.side
Circle: def area(self): return 3.14 * self.radius ** 2

💡 Hint

Remember to use self to access instance variables.

Methods must include self and use it to access instance variables. The formulas must be correct for area.

🚀 Application

expert

Polymorphism in Function Arguments

What will be the output of this code that uses polymorphism in function arguments?

Python

class Printer:
    def print_message(self):
        print("Generic message")

class EmailPrinter(Printer):
    def print_message(self):
        print("Email message")

class SMSPrinter(Printer):
    def print_message(self):
        print("SMS message")

def send_notification(printer: Printer):
    printer.print_message()

send_notification(EmailPrinter())
send_notification(SMSPrinter())
send_notification(Printer())

A

SMS message
Email message
Generic message

B

Email message
SMS message
Generic message

C

Email message
Email message
Email message

D

Generic message
Generic message
Generic message

💡 Hint

Each subclass overrides print_message. The function calls the method on the passed object.

The function send_notification calls print_message on the object passed. Polymorphism ensures the correct method runs based on the object's class.