Python Coding challenge - Day 1036| What is the output of the following Python Code?

 

Code Explanation:

1. Importing ABC Tools

from abc import ABC, abstractmethod

Imports:

ABC → Base class for creating abstract classes

abstractmethod → Decorator to mark methods as mandatory to override

📌 Used to enforce method implementation in subclasses.

🔹 2. Defining an Abstract Base Class A

class A(ABC):

A inherits from ABC

This makes A an abstract class

Abstract classes cannot be instantiated directly

🔹 3. Declaring an Abstract Method

@abstractmethod

def f(self): pass

Declares f() as an abstract method

Any concrete subclass must provide an implementation

pass means no implementation in A

📌 If a subclass doesn’t implement f, it cannot be instantiated

🔹 4. Defining Subclass B

class B(A):

B inherits from abstract class A

Python checks whether B implements all abstract methods

🔹 5. Implementing the Abstract Method (Tricky Part)

f = lambda self: 10

Assigns a function object to f

This counts as implementing the abstract method

Equivalent to:

def f(self):

    return 10

📌 Python does not care about syntax, only that f exists and is callable.

🔹 6. Creating an Object of B

B()

Allowed because:

All abstract methods are implemented

B is now a concrete class

🔹 7. Calling the Method

print(B().f())

Step-by-step:

B() → creates an instance of B

.f() → calls the lambda method

Lambda returns 10

print() prints the value

✅ Final Output

10

100 Python Programs for Beginner with explanation