Python Coding challenge - Day 891| What is the output of the following Python Code?

 

Code Explanation:

1. Defining the Class

class Data:

This creates a new class named Data.

A class is a blueprint for creating objects (instances) that can hold data and behavior.

2. Defining the Constructor (__init__)

    def __init__(self, v):

        self.v = v

__init__ is the constructor method. It runs automatically when you create a new Data object.

Parameter v is the value passed while creating the object.

self.v = v stores that value in an instance attribute named v.

So each Data object will have its own v.

3. Defining __repr__ (Representation Method)

    def __repr__(self):

        return f"Value={self.v}"

__repr__ is a magic (dunder) method that defines how the object is represented as a string, mainly for debugging or interactive console.

When you do print(d) or just type d in a Python shell, Python calls __repr__ (if __str__ isn’t defined).

It returns a formatted string:

f"Value={self.v}" → uses f-string to embed the value of self.v.

For example, if self.v = 9, it returns "Value=9".

4. Creating an Object

d = Data(9)

This creates an instance d of the Data class.

__init__ is called with v = 9.

Inside __init__, self.v is set to 9.

So now d.v == 9.

5. Printing the Object

print(d)

When you pass d to print(), Python looks for:

First: __str__ method (not defined here)

Then: __repr__ method (defined!)

So it calls d.__repr__(), which returns "Value=9".

print outputs:

Value=9

Final Output

Value=9

700 Days Python Coding Challenges with Explanation