Python Coding challenge - Day 1096| What is the output of the following Python Code?

 

Code Explanation:

1. Defining Class D (Descriptor Class)

class D:

Here, a class D is defined. This class will act as a descriptor because it implements special methods like __get__.

2. Defining __get__ Method

def __get__(self, obj, objtype):

    return 50

__get__ is a descriptor method.

It is automatically called when the attribute is accessed.

self → instance of descriptor (D)

obj → instance of class A (i.e., a)

objtype → class A

It always returns 50, no matter what.

3. Defining Class A

class A:

A normal class is created.

4. Assigning Descriptor to Attribute x

x = D()

Here, x is assigned an instance of class D.

This makes x a descriptor attribute of class A.

5. Creating Object of Class A

a = A()

An object a of class A is created.

6. Assigning Value to a.x

a.x = 10

This creates an instance attribute x inside object a.

Normally, this would override the class attribute.

BUT: since D is a non-data descriptor (only __get__, no __set__),

instance attribute takes priority.

7. Accessing a.x

print(a.x)

Python first checks instance dictionary → finds x = 10

Since descriptor has no __set__, it is a non-data descriptor

So instance value is used instead of descriptor

Final Output

10

 Book:  500 Days Python Coding Challenges with Explanation