Introduction
“Python loops for beginners are essential to automate tasks and repeat code efficiently. In this post, we’ll explore for loops, while loops, and nested loops with practical examples.
Welcome back, Python learners!
In Post 4, we learned how to make Python decide what to do using if, elif, and else statements.
But what if we want Python to do something again and again — for example:
Print numbers from 1 to 100
Go through every item in a list
Repeat a task until the user wants to stop
That’s where loops come in!
What Are Loops?
A loop allows you to execute a block of code multiple times without writing it repeatedly.
For example:
print(“Hello”)
print(“Hello”)
print(“Hello”)
This repeats the same code 3 times. Instead, we can use a loop to do it automatically!
Types of Loops in Python
Python has two main types of loops:
for loop — runs a fixed number of times
while loop — runs until a condition becomes False
Let’s explore both!
1. The for Loop
The for loop is used to iterate (loop) over a sequence — like a list, string, or range of numbers.
Basic Syntax:
for variable in sequence:
Example 1: Using range()
for i inrange(5):
print(“Hello, Python!”)
Output:
Hello, Python!
Hello, Python!
Hello, Python!
Hello, Python!
Hello, Python!
range(5) means: 0, 1, 2, 3, 4 (it stops before 5).
Example 2: Print numbers from 1 to 10
for i inrange(1, 11):
print(i)
🧾 Output:
1
2
3
4
5
6
7
8
9
10
Example 3: Loop through a list
fruits = [“apple”, “banana”, “mango”]
for fruit in fruits:
print(“I like”, fruit)
🧾 Output:
I like apple
I like banana
I like mango
Example 4: Loop through a string
for letter in”Python”:
print(letter)
Output:
P
y
t
h
o
n
2. The while Loop
The while loop repeats code as long as a condition is True.
Syntax:
while condition:
Example 1: Print numbers 1 to 5
i =
while i <= 5:
print(i)
i +=
Output:
1
2
3
4
5
Be careful!
If you forget to update the variable (like i += 1), you’ll create an infinite loop that never stops.
Example 2: Countdown Timer
count =
while count > 0:
print(count)
count -=
print(“Time’s up!”)
Output:
5
4
3
2
1
Time’s up!
Combining Loops and Conditions
You can use loops with if statements to make powerful logic.
Example: Print even numbers from 1 to 10
for i inrange(1, 11):
if i % 2 == 0:
print(i)
🧾 Output:
2
4
6
8
10
Breaking and Skipping Loops
Sometimes you may want to:
Stop the loop early → use break
Skip one iteration → use continue
Example 1: Using break
for i inrange(1, 10):
if i == 5:
print(i)
Output:
1
2
3
4
The loop stopped when i == 5.
Example 2: Using continue
for i inrange(1, 10):
if i == 5:
print(i)
Output:
1
2
3
4
6
7
8
9
The loop skipped printing 5.
Nested Loops (Loop inside a Loop)
Sometimes, you need one loop inside another loop.
Example:
for i inrange(1, 4):
for j inrange(1, 4):
print(i, j)
Output:
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
Fun Example: Multiplication Table
num = int(input(“Enter a number: “))
for i inrange(1, 11):
print(num, “x”, i, “=”, num * i)
Output Example:
Enter a number: 5
5 x 1 = 5
5 x 2 = 10
…
5 x 10 = 50
Bonus: Infinite Loop Example (Be Careful!)
whileTrue:
name = input(“Enter your name (type ‘exit’ to stop): “)
if name.lower() == “exit”:
print(“Hello,”, name)
Output Example:
Enter your name (type’exit’to stop): John
Hello, John
Enter your name (type’exit’to stop): exit
Practice Tasks
Try these to master loops
Print all odd numbers between 1 and 50.
Write a program that prints the sum of numbers from 1 to 100.
Ask the user for a number and check if it’s prime or not (using a loop).
Print this pattern:
*
* *
* * *
* * * *
* * * * *
Create a menu-driven program using while True that lets users:
Add two numbers
Subtract two numbers
Exit when they choose
Summary
You’ve learned:
How to use for loops and while loops
The difference between fixed and conditional looping
Using break, continue, and nested loops
Real-world examples like calculators and patterns
Loops make your programs automated and efficient — you’ll use them constantly as a Python developer!
