Purpose of inheritance in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this inheritance example?

Look at the code below. What will it print when run?

Python

class Animal:
    def speak(self):
        return "I make a sound"

class Dog(Animal):
    def speak(self):
        return "Woof!"

pet = Dog()
print(pet.speak())

A AttributeError

B I make a sound

C TypeError

D Woof!

💡 Hint

Remember, the Dog class changes the speak method.

The Dog class inherits from Animal but replaces the speak method. So calling speak on a Dog object runs Dog's version, printing "Woof!".

🧠 Conceptual

intermediate

Why use inheritance in programming?

Which of these is the main purpose of inheritance?

A To reuse code and create a relationship between classes

B To make programs run faster

C To hide all data from users

D To prevent any changes to code

💡 Hint

Think about how inheritance helps avoid repeating code.

Inheritance allows one class to use code from another, making it easier to share and extend behavior without rewriting code.

❓ Predict Output

advanced

What is the output of this multi-level inheritance?

What will this code print?

Python

class A:
    def greet(self):
        return "Hello from A"

class B(A):
    def greet(self):
        return "Hello from B"

class C(B):
    pass

obj = C()
print(obj.greet())

A Hello from B

B Hello from A

C AttributeError

D TypeError

💡 Hint

Check which class defines greet and which classes inherit it.

Class C inherits from B, which overrides greet from A. Since C does not override greet, it uses B's version.

🔧 Debug

advanced

Which option causes an error in inheritance?

Which code snippet will cause an error when run?

A

class Parent:
    def greet(self):
        return "Hi"
class Child(Parent):
    def greet(self):
        return super().greet() + " there"
obj = Child()
print(obj.greet())

B

class Parent:
    def __init__(self):
        self.value = 5
class Child(Parent):
    def __init__(self):
        super().__init__()
        self.value = 10
obj = Child()
print(obj.value)

C

class Parent:
    def __init__(self):
        self.value = 5
class Child(Parent):
    def __init__(self):
        pass
obj = Child()
print(obj.value)

D

class Parent:
    pass
class Child(Parent):
    pass
obj = Child()

💡 Hint

Look at how the Child class initializes value and if it calls the Parent constructor.

Option C's Child __init__ does not call Parent's __init__, so self.value is never set. This causes AttributeError when accessing obj.value.

🧠 Conceptual

expert

What is the main benefit of method overriding in inheritance?

Why do programmers override methods in child classes?

A To prevent the parent class method from running ever

B To change or extend the behavior of a method from the parent class

C To make the program run slower for debugging

D To copy the parent method exactly without changes

💡 Hint

Think about how child classes customize behavior.

Overriding lets child classes provide their own version of a method, changing or adding to what the parent class does.