Python Coding challenge - Day 1232| What is the output of the following Python Code?

 

Code Explanation:

🔹 1. Importing dataclass and replace

from dataclasses import dataclass, replace

✅ Explanation

dataclass and replace are imported from Python's built-in dataclasses module.

@dataclass automatically creates useful methods like:

__init__()

__repr__()

__eq__()

replace() creates a new object by copying an existing dataclass object and changing selected fields.

dataclasses Module

       │

       ▼

 ┌───────────────┐

 │ @dataclass    │

 │ replace()     │

 └───────────────┘

Nothing executes yet.

🔹 2. Creating a Dataclass

@dataclass

class User:

    age: int

✅ Explanation

@dataclass converts the normal class into a dataclass.

Python automatically creates something similar to:

class User:

    def __init__(self, age):

        self.age = age

Current Memory

User Class

Field

age : int

No object is created yet.

🔹 3. Creating an Object

u = User(20)

✅ Explanation

An object named u is created.

Python automatically calls:

User(age=20)

Current Memory

u

▼

+------------+

| age = 20   |

+------------+

Visual Representation

User Object

age

20

🔹 4. Using replace()

replace(u, age=30)

✅ Explanation

replace() does not modify the original object.

Instead, it:

Copies the object.

Changes the specified field.

Returns a new object.

Current Memory

Original Object

u

age = 20

↓

replace()

↓

New Object

age = 30

Visual Representation

        u

        │

        ▼

   +-----------+

   | age = 20  |

   +-----------+

        │

replace(age=30)

        ▼

   +-----------+

   | age = 30  |

   +-----------+

Notice

The original object is unchanged.

🔹 5. Accessing .age

replace(u, age=30).age

✅ Explanation

replace() returns a new object.

Python immediately accesses its age attribute.

Returned value

30

🔹 6. Printing the Result

print(replace(u, age=30).age)

✅ Explanation

Python prints the value of the age attribute from the new object.

Output

30

🎯 Final Output

30