Python Coding challenge - Day 1222| What is the output of the following Python Code?

 

Code Explanation:

🔹 1. Importing the weakref Module

import weakref

✅ Explanation

weakref is Python's built-in module for creating weak references to objects.

It lets you work with objects without increasing their reference count.

It is commonly used for memory management and cleanup operations.

Think of it as a watcher that monitors an object.

Program

↓

weakref Module

↓

Watch Objects

↓

Perform Cleanup

Nothing is created yet.

🔹 2. Creating a Class

class Test:

    pass

✅ Explanation

A class named Test is created.

pass means the class has no attributes or methods.

It is simply a blueprint for creating objects.

Current Structure

Test

↓

Empty Class

No object exists yet.

🔹 3. Creating an Object

obj = Test()

✅ Explanation

Python creates an object of the Test class.

Current Memory

obj

↓

<Test Object>

Visual Representation

obj

↓

┌──────────┐

│  Test    │

└──────────┘

The object is alive in memory.

🔹 4. Registering a Finalizer

f = weakref.finalize(obj, print, "Destroyed")

✅ Explanation

This is the most important line.

weakref.finalize() registers a function that will automatically run when obj is garbage collected.

Syntax:

weakref.finalize(object, function, *arguments)

Here,

Object → obj

Function → print

Argument → "Destroyed"

Current Memory

obj

↓

<Test Object>

      │

      ▼

Finalizer

↓

print("Destroyed")

The message is not printed now.

It is only scheduled for the future.

🔹 5. Understanding the Finalizer

✅ Explanation

weakref.finalize() creates a finalizer object.

Current Memory

f

↓

Finalize Object

Its job is:

Wait

↓

Object Destroyed

↓

Run print("Destroyed")

It continuously watches the object.

🔹 6. Checking the alive Property

f.alive

✅ Explanation

The alive attribute tells whether the finalizer is still active.

Current Situation

Object Exists

↓

Yes

↓

Finalizer Active

↓

alive = True

Since obj still exists, the finalizer has not executed.

Returned value

True

🔹 7. Printing the Result

print(f.alive)

✅ Explanation

Python prints the value of f.alive.

Output

True

🎯 Final Output

True