🔁 Introduction

Loops: Stop Repeating Yourself

Programmers are notoriously lazy. We hate writing the same code twice. If you need to print "Hello" 100 times, you don't write print("Hello") 100 times. You write it once, and tell Python to repeat it 100 times using a Loop.

Computers never get bored. They will happily count to a million without complaining. Let them do the boring, repetitive work for you!

🔂 The "For" Loop

When you know exactly how many times to repeat

A for loopA loop that repeats a specific block of code a set number of times. is perfect for when you know exactly how many times you want an action to happen. We often use it with a handy built-in function called range().

for_loop.py
for i in range(5):
    print("Push-up number:", i)for i in range(5):"Hey Python, repeat this 5 times. Use i to keep track of the current number." (Don't forget the colon!)
    print(...)Indented code! Python starts counting at 0, so this prints: 0, 1, 2, 3, 4.

🔄 The "While" Loop

Repeat until a condition changes

A while loopA loop that keeps running over and over as long as its condition remains True. doesn't care about numbers. It cares about conditions (just like the if statements we just learned!). It says: "Keep doing this while the condition is True."

while_loop.py
energy = 3

while energy > 0:
    print("Coding...")
    energy = energy - 1
    
print("Time for a nap.")while energy > 0:As long as energy is greater than 0, run the indented code below.
    energy = energy - 1CRITICAL STEP: We reduce the energy. If we didn't do this, energy would always be 3, and the loop would run forever!

👻 The Infinite Loop

If a while loop's condition never becomes False, it runs forever. It will freeze your program and heat up your computer. Always make sure something inside the loop changes the condition!

🛑 Break & Continue

Taking control of your loops

Sometimes you need to escape a loop early, or skip a step.

break: Immediately destroys the loop and escapes it entirely.
continue: Skips the rest of the current loop iteration, and jumps straight back to the top for the next round.

for i in range(10):
    if i == 3:
        continue  # skips 3
    if i == 7:
        break     # completely stops the loop at 7
    print(i)

# Output will be: 0 1 2 4 5 6

💡 Real-Life Analogy

For Loop: Doing 10 pushups. You know exactly how many you are going to do before you start. "For every number from 1 to 10, do a pushup."

While Loop: Eating pizza slices until you are full. You don't know how many slices it will take. You just keep taking a slice "while" you are still hungry.

🖼️ Diagram

The Loop Cycle

The code executes, then jumps back up to check the condition again. It keeps doing this until the condition becomes False.

😂 Sarpanch's Corner

The Infinite Mistake

Panel 1

"I'll write a while loop to count sheep so I can sleep!"

sheep = 1
while sheep > 0:
  print(sheep)

Panel 2

"...1043... 1044... 1045..."

Hours pass. The computer fans are screaming.

Panel 3

"...84920... 84921... HELP ME..."

He forgot to change the condition. Infinite loop.

🚀 Try It Yourself

Looping in Action

Experiment with loops. Try changing the range or the while condition.

💡 Challenges:

Change the for loop to repeat 10 times instead of 5.
In the while loop, change it to count down from 5 to 0. (Set countdown to 5).
Advanced: Try adding an if statement inside the for loop to break if i == 3.

✅ Summary

Doing Things Again — Done! 🔁

Loops let you run the same block of code multiple times.
A for loop is used when you know exactly how many times you want to loop. (e.g., for i in range(5):)
A while loop is used when you want to loop until a certain condition becomes False.
Infinite loops happen when your while condition never becomes False. Always update your variables!
break destroys the loop and escapes.
continue skips the rest of the current round and goes to the next round.

You're a looping master! Just be careful not to get stuck in an infinite loop. We're halfway through the basics. Next up: Grouping stuff together in lists! 📦