Python Coding challenge - Day 1091| What is the output of the following Python Code?

 

Code Explanation:

1️⃣ Importing the Module

import threading

Explanation

Imports the threading module.

Enables creation and management of multiple threads.

2️⃣ Creating an Empty List

threads = []

Explanation

A list named threads is created.

It will store all thread objects so we can later wait for them using join().

3️⃣ Starting the Loop

for i in range(3):

Explanation

Loop runs 3 times.

Values of i:

0, 1, 2

4️⃣ Creating the Thread (Important)

t = threading.Thread(target=lambda: print(i))

Explanation

A new thread is created.

target=lambda: print(i) means:

Each thread will execute a lambda function that prints i.

⚠️ Critical Concept: Late Binding

The lambda does NOT capture the value of i at that moment.

Instead, it captures the reference to variable i.

By the time threads execute, loop has finished → i = 2.

👉 So all threads will use the same final value of i.

5️⃣ Storing the Thread

threads.append(t)

Explanation

Thread is added to the list.

This helps later to join all threads.

6️⃣ Starting the Thread

t.start()

Explanation

Starts execution of the thread.

The lambda function will run concurrently.

7️⃣ Joining All Threads

for t in threads:

    t.join()

Explanation

Ensures the main program waits for all threads to finish.

Prevents premature program exit.

📤 Final Output

2

2

2

900 Days Python Coding Challenges with Explanation