Extending parent behavior in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of extended method with super() call

What is the output of this Python code when calling Child().greet()?

Python

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

class Child(Parent):
    def greet(self):
        parent_msg = super().greet()
        return parent_msg + " and Child"  

print(Child().greet())

A "Hello from Parent and Child"

B "Hello from Child"

C "Hello from Parent"

D TypeError

💡 Hint

Think about how super() calls the parent method and how the strings are combined.

The Child class calls super().greet() which returns "Hello from Parent". Then it adds " and Child" to that string, so the final output is "Hello from Parent and Child".

❓ Predict Output

intermediate

Output when parent method is not called

What will be printed when running this code?

Python

class Parent:
    def action(self):
        print("Parent action")

class Child(Parent):
    def action(self):
        print("Child action")

obj = Child()
obj.action()

A Child action

B Parent action

C Parent action\nChild action

D AttributeError

💡 Hint

Check which method is called when the child overrides the parent method without calling super().

The Child class overrides the action method and does not call super(). So only "Child action" is printed.

🔧 Debug

advanced

Why does this code raise an error?

This code tries to extend the parent method but raises an error. What is the cause?

Python

class Parent:
    def calculate(self, x):
        return x * 2

class Child(Parent):
    def calculate(self, x):
        return super().calculate(x) + 3

print(Child().calculate(4))

A SyntaxError due to missing colon

B Missing return statement in Child.calculate

C Parent.calculate requires two arguments

D super is used without parentheses, causing AttributeError

💡 Hint

Check how super() is called in Python 3.

In Python 3, super() must be called with parentheses to get the super object. Using super.calculate(x) causes an AttributeError because super is a built-in function, not an object.

❓ Predict Output

advanced

Output of multiple inheritance with super()

What is the output of this code?

Python

class A:
    def process(self):
        return "A"

class B(A):
    def process(self):
        return super().process() + "B"

class C(A):
    def process(self):
        return super().process() + "C"

class D(B, C):
    def process(self):
        return super().process() + "D"

print(D().process())

A "ABDC"

B "ABCD"

C "ACBD"

D "AB"

💡 Hint

Remember Python uses Method Resolution Order (MRO) in multiple inheritance.

The MRO for class D is D -> B -> C -> A. Each super().process() calls the next in line: D calls B, B calls C, C calls A, resulting in "A" (A) + "C" (C) + "B" (B) + "D" (D) = "ACBD".

🧠 Conceptual

expert

Why use super() in method overriding?

Which of the following best explains why we use super() when overriding a method in a child class?

A To prevent the child class method from running

B To call the parent class method and extend its behavior without rewriting it

C To create a new method unrelated to the parent class

D To call a method from a sibling class

💡 Hint

Think about how inheritance helps reuse code.

Using super() allows the child class to run the parent class method, then add or change behavior, so we don't have to rewrite the parent's code.