Method overriding behavior in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of method overriding with super()

What is the output of this Python code?

Python

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

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

obj = Child()
print(obj.greet())

A TypeError

B Hello from Parent

C and Child

D Hello from Parent and Child

💡 Hint

Think about how super() calls the parent method and how the returned string is combined.

The Child class overrides greet but calls the Parent's greet using super(). The returned string from Parent is combined with ' and Child', so the final output is 'Hello from Parent and Child'.

❓ Predict Output

intermediate

Output when overriding without calling super()

What will this code print?

Python

class Base:
    def message(self):
        return "Base message"

class Derived(Base):
    def message(self):
        return "Derived message"

obj = Derived()
print(obj.message())

A AttributeError

B Derived message

C None

D Base message

💡 Hint

The Derived class replaces the Base method without calling it.

Since Derived overrides message and does not call super(), the method from Derived is used, printing 'Derived message'.

❓ Predict Output

advanced

Output with multiple inheritance and method overriding

What is the output of this code?

Python

class A:
    def speak(self):
        return "A speaks"

class B(A):
    def speak(self):
        return "B speaks"

class C(A):
    def speak(self):
        return "C speaks"

class D(B, C):
    pass

obj = D()
print(obj.speak())

A B speaks

B A speaks

C C speaks

D TypeError

💡 Hint

Check the method resolution order (MRO) for class D.

Class D inherits from B and C. Python uses MRO and finds speak in B first, so 'B speaks' is printed.

❓ Predict Output

advanced

Output when overriding a method and changing return type

What will this code print?

Python

class Parent:
    def get_value(self):
        return 10

class Child(Parent):
    def get_value(self):
        return "Ten"

obj = Child()
print(obj.get_value())

A Ten

B TypeError

C 10

D AttributeError

💡 Hint

The Child method returns a string instead of an integer.

The Child class overrides get_value and returns the string 'Ten'. Python allows this change in return type, so 'Ten' is printed.

❓ Predict Output

expert

Output with method overriding and attribute access

What is the output of this code?

Python

class Parent:
    def __init__(self):
        self.value = 5
    def get_value(self):
        return self.value

class Child(Parent):
    def __init__(self):
        self.value = 10
    def get_value(self):
        return super().get_value() + 5

obj = Child()
print(obj.get_value())

A 10

B 5

C 15

D AttributeError

💡 Hint

Consider which __init__ method runs and what self.value is when super().get_value() is called.

Child's __init__ does not call Parent's __init__, so Parent's self.value is never set. Child sets self.value to 10. But super().get_value() uses Parent's method which accesses self.value on the Child instance, which is 10. So super().get_value() returns 10, then +5 makes 15. However, since Parent's __init__ is not called, self.value is set by Child to 10. So output is 15.