Inheriting attributes and methods in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of inherited method call

What is the output of this Python code that uses inheritance?

Python

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

class Dog(Animal):
    pass

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

A AttributeError

B "Dog barks"

C "I am an animal"

D "I make a sound"

💡 Hint

The Dog class does not override the speak method.

Since Dog inherits from Animal and does not override speak, calling speak on Dog instance uses Animal's speak method, returning "I make a sound".

❓ Predict Output

intermediate

Value of inherited attribute after modification

What is the value of pet.color after running this code?

Python

class Animal:
    def __init__(self):
        self.color = "brown"

class Dog(Animal):
    def __init__(self):
        super().__init__()
        self.color = "black"

pet = Dog()

A "black"

B "brown"

C None

D AttributeError

💡 Hint

The Dog class calls super().__init__() then changes color.

Dog's __init__ calls Animal's __init__ setting color to "brown", then immediately sets color to "black". So pet.color is "black".

🔧 Debug

advanced

Identify the error in method overriding

What error does this code raise when executed?

Python

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

class Dog(Animal):
    def speak():
        return "bark"

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

A "bark"

B AttributeError: 'Dog' object has no attribute 'speak'

C TypeError: speak() missing 1 required positional argument: 'self'

D SyntaxError

💡 Hint

Check the method signature of speak in Dog.

Dog's speak method lacks the self parameter, so calling pet.speak() passes self implicitly but method expects none, causing TypeError.

❓ Predict Output

advanced

Output of method overriding with super()

What is printed when this code runs?

Python

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

class Dog(Animal):
    def speak(self):
        return super().speak() + " and bark"

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

A "bark"

B "sound and bark"

C "sound"

D AttributeError

💡 Hint

super() calls the parent class method.

Dog's speak calls Animal's speak via super(), which returns "sound", then adds " and bark". So output is "sound and bark".

🧠 Conceptual

expert

Number of attributes in instance after inheritance and modification

Given the code below, how many attributes does the instance 'pet' have?

Python

class Animal:
    def __init__(self):
        self.legs = 4
        self.color = "brown"

class Dog(Animal):
    def __init__(self):
        super().__init__()
        self.color = "black"
        self.tail = True

pet = Dog()

A 3

B 2

C 4

D 1

💡 Hint

Count all attributes set on pet after Dog.__init__ runs.

pet has legs (from Animal), color (overwritten in Dog), and tail (added in Dog), total 3 attributes.