Website: www.codeswithpankaj.com
Author: Pankaj Chouhan

Welcome to Codes With Pankaj! In this tutorial, we’ll explore Python loops, a fundamental concept that lets you repeat tasks efficiently in your code. Whether you’re printing numbers or processing data, loops make your life as a coder easier. Let’s dive in step by step!

1. What Are Loops?
2. Types of Loops in Python
3. The for Loop
   • Step 1: Understanding the for Loop
   • Step 2: Syntax and Example
   • Step 3: Using range()
   • Step 4: Looping Through Lists
4. The while Loop
   • Step 5: Understanding the while Loop
   • Step 6: Syntax and Example
5. Loop Control Statements
   • Step 7: Using break
   • Step 8: Using continue
6. Practice Exercises
7. What’s Next?

A loop in programming allows you to repeat a block of code multiple times. Imagine you want to print "Hello, Pankaj!" 5 times. Writing print("Hello, Pankaj!") five times is tedious. Loops let you do this with just a few lines of code!

In Python, there are two main types of loops:

• for loop: Used when you know how many times you want to repeat something.
• while loop: Used when you want to repeat until a condition is met.

Let’s explore both with simple examples.

Python offers two primary loops:

1. for loop: Iterates over a sequence (like a list, string, or range of numbers).
2. while loop: Repeats as long as a condition is true.

We’ll break down each loop with examples you can try yourself.

The for loop is perfect for repeating tasks a specific number of times or iterating over items in a sequence (like a list or string).

Here’s the basic syntax of a for loop:

for variable in sequence:
    # Code block to repeat

Example: Print numbers 1 to 5.

for num in [1, 2, 3, 4, 5]:
    print(num)

Output:

1
2
3
4
5

In this example:

• num is the loop variable that takes each value in the list [1, 2, 3, 4, 5].
• The print(num) statement runs for each value of num.

The range() function generates a sequence of numbers, making it super useful with for loops.

Example: Print numbers 0 to 4.

for i in range(5):
    print(i)

Output:

0
1
2
3
4

Explanation:

• range(5) generates numbers from 0 to 4 (5 numbers total, starting at 0).
• You can also specify a start and end: range(1, 6) gives 1 to 5.

Try this:

for i in range(1, 6):
    print(f"Number: {i}")

Output:

Number: 1
Number: 2
Number: 3
Number: 4
Number: 5

You can loop through any list, not just numbers.

Example: Print each fruit in a list.

fruits = ["apple", "banana", "orange"]
for fruit in fruits:
    print(f"I love {fruit}!")

Output:

I love apple!
I love banana!
I love orange!

Tip: The loop variable (fruit) takes each item in the list one by one.

The while loop keeps running as long as a condition is true. It’s great when you don’t know how many times you’ll need to loop.

Here’s the syntax:

while condition:
    # Code block to repeat

Example: Print numbers 1 to 5.

count = 1
while count <= 5:
    print(count)
    count += 1

Output:

1
2
3
4
5

Explanation:

• count = 1 sets the starting value.
• The loop runs while count <= 5 is true.
• count += 1 increases count by 1 each time to avoid an infinite loop.

Warning: Always ensure the condition will eventually become false, or you’ll get an infinite loop!

Try this:

number = 10
while number > 0:
    print(f"Countdown: {number}")
    number -= 2

Output:

Countdown: 10
Countdown: 8
Countdown: 6
Countdown: 4
Countdown: 2

Sometimes, you want to control how a loop behaves. Python provides two useful statements: break and continue.

The break statement stops the loop immediately.

Example: Stop the loop when you find a specific number.

for i in range(1, 10):
    if i == 5:
        break
    print(i)

Output:

1
2
3
4

Explanation: The loop stops when i equals 5, so 5 and higher numbers aren’t printed.

The continue statement skips the rest of the current loop iteration and moves to the next one.

Example: Skip printing even numbers.

for i in range(1, 6):
    if i % 2 == 0:
        continue
    print(f"Odd number: {i}")

Output:

Odd number: 1
Odd number: 3
Odd number: 5

Explanation: When i is even (divisible by 2), continue skips the print statement.

Ready to test your skills? Try these exercises and check your answers on www.codeswithpankaj.com!

1. Exercise 1: Write a for loop to print all even numbers from 2 to 10.
2. Exercise 2: Use a while loop to print "Hello, Pankaj!" 3 times.
3. Exercise 3: Write a for loop that stops when it reaches the number 7 (use break).
4. Exercise 4: Write a loop that skips printing the number 4 (use continue).

Sample Solution (Exercise 1):

for i in range(2, 11, 2):
    print(i)

Output:

2
4
6
8
10

Visit www.codeswithpankaj.com for solutions to all exercises!

• Try it yourself: Copy the code examples into a Python editor (like IDLE, VS Code, or an online editor like Replit) and run them.
• Experiment: Change numbers or conditions in the examples to see what happens.
• Ask for help: If you’re stuck, leave a comment on our website or join the Codes With Pankaj community!