Python Loops – for, while, and nested loops explained

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Python Loops – for, while, and nested loops explained

Introduction

Loops are one of the most powerful features in programming.
They allow you to repeat a block of code multiple times, making your program shorter and more efficient.
Python supports two main types of loops:

  1. for loop

  2. while loop

1. The for Loop

A for loop is used to iterate over a sequence (like a list, tuple, string, or range).

Example:

for i in range(5):
    print("Hello, Habbit2Code Online Coding Classes!")

Output:

Hello, Habbit2Code Online Coding Classes!
Hello, Habbit2Code Online Coding Classes!
Hello, Habbit2Code Online Coding Classes!
Hello, Habbit2Code Online Coding Classes!
Hello, Habbit2Code Online Coding Classes!

Example 2: Loop through a list

fruits = ["apple", "banana", "cherry"]
for item in fruits:
    print(item)

Output:

apple
banana
cherry

2. The while Loop

The while loop runs as long as a condition is true.

Example:

count = 1
while count <= 5:
    print("Count =", count)
    count += 1

Output:

Count = 1
Count = 2
Count = 3
Count = 4
Count = 5

3. The break and continue Statements

  • break → exits the loop completely.

  • continue → skips the current iteration and moves to the next one.

Example:

for i in range(1, 6):
    if i == 3:
        continue
    if i == 5:
        break
    print(i)

Output:

1
2
4

4. Nested Loops

A loop inside another loop is called a nested loop.

Example:

for i in range(1, 4):
    for j in range(1, 4):
        print(f"({i}, {j})", end=" ")
    print()

Output:

(1, 1) (1, 2) (1, 3)
(2, 1) (2, 2) (2, 3)
(3, 1) (3, 2) (3, 3)

5. Real-Life Example

Let’s print all even numbers between 1 and 20 using a loop.

for num in range(1, 21):
    if num % 2 == 0:
        print(num)

Output:

2, 4, 6, 8, ..., 20

Challenge for You

Write a program that prints a multiplication table for any number entered by the user using a for loop.

Final Thoughts

  • Use for when you know how many times to loop.

  • Use while when you don’t.

  • Add break and continue to control the flow inside loops.

Mastering loops is a huge step toward writing efficient, professional Python code.

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