Python Coding challenge - Day 1017| What is the output of the following Python Code?

 

Code Explanation:

1. Defining the descriptor class

class D:

This defines a class named D.

Objects of this class will be used as descriptors.

2. Implementing __get__

    def __get__(self, obj, owner):

        return "D"

__get__ makes D a descriptor.

Parameters:

self → the descriptor object (D()).

obj → the instance accessing the attribute (c).

owner → the class (C).

Whenever x is accessed, this method returns "D".

3. Implementing __set__

    def __set__(self, obj, val):

        pass

Presence of __set__ makes D a data descriptor.

Data descriptors have higher priority than instance attributes.

This method ignores assignments but still controls access.

4. Defining the owner class

class C:

This defines a class named C.

5. Assigning the descriptor

    x = D()

x is a class attribute.

It is managed by the data descriptor D.

6. Creating an instance

c = C()

An object c of class C is created.

Initially, c.__dict__ is empty.

7. Manually inserting an instance attribute

c.__dict__['x'] = "I"

This directly adds an instance attribute x with value "I".

Normally, instance attributes override class attributes…

But not data descriptors.

8. Accessing the attribute

print(c.x)

🔍 Attribute lookup order (important here):

Data descriptors

Instance attributes (c.__dict__)

Non-data descriptors

Class attributes

x is a data descriptor.

Python calls D.__get__ before checking c.__dict__.

The instance attribute "I" is ignored.

✅ Final Output

D

100 Python Programs for Beginner with explanation