Loops in Python – Complete Guide with Examples

In this lecture we will cover : Loops in Python: Ultimate Beginner’s Guide to For, While, Break, Continue & range()

Loops are a fundamental concept in programming that allow us to execute a block of code multiple times. In Python, loops help reduce redundancy, make code concise, and improve readability.

This lecture covers:

• What are Loops?
• while Loops
• for Loops and range()
• break Statement
• continue Statement
• Nested Loops

What are Loops in Python?

Definition:

A loop is a programming construct that iterates through a block of code as long as a particular condition is true.
Python includes two primary categories of loops that are most commonly employed:

1. while loop

2. for loop

While Loops in Python

Definition:

A while loop keeps executing the block of code as long as the condition is true.

Syntax:

while condition:
    # code block

range() in Python:

Definition:

The function range() creates a sequence of numbers to be used for for loops most of the time.

Syntax:

range(start, stop, step)

• start (optional) – starting number (default is 0)

• stop – generates up to this number (not inclusive)

• step (optional) – difference between each number (default is 1)

For Loops in Python

Definition:

A for loop is utilized for traversing the elements of some arrays such as lists, tuples, or ranges.

Syntax:

for item in sequence:
    # code block

Break in Python

Definition:

The break statement is utilized for leaving the loop prematurely, regardless of whether the loop condition is still true.

Continue in Python

Definition:

The continue statement helps to skip the current iteration and reach the next one.

Nested Loops in Python

Definition:

A nested loop is a loop that is defined inside another loop. Whenever the outer loop is executed, the inner loop is executed in full.

Summary Table

Concept	Use	Example
while loop	Loop until a condition is false	while count < 5:
for loop	Loop over sequences or ranges	for i in range(5):
range()	Generate sequence of numbers	range(1, 10, 2)
break	Exit loop early	if x == 5: break
continue	Skip current iteration	if x == 3: continue
Nested loops	Loop inside a loop	for x in range(3): for y in ...

🧠 Frequently Asked Questions (FAQs) About Loops in Python

❓ What is the difference between for and while loops in Python?

The main difference lies in how they repeat:

for loop is used when you know how many times you want to run a block of code. It’s often used with functions like range(), lists, or strings.

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

while loop is used when you want to repeat until a condition is no longer true, and you might not know in advance how many times it will run.

i = 0
while i < 5:
    print(i)
    i += 1

❓ When should I use break in a Python loop?

Use break when you want to exit the loop early, before the loop naturally finishes all iterations.

Example:

for num in range(10):
    if num == 5:
        break
    print(num)

This loop stops printing when num reaches 5.

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❓ What does continue do in Python loops?

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

Example:

for num in range(5):
    if num == 2:
        continue
    print(num)

Output: 0 1 3 4 — Notice how 2 was skipped.

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❓ Can loops be nested in Python?

Yes! You can write a loop inside another loop, which is called a nested loop. It’s useful for working with 2D data structures like matrices or grids.

Example:

for i in range(3):
    for j in range(2):
        print(f"i={i}, j={j}")

❓ What is the use of range() in Python loops?

The range() function is commonly used with for loops to generate a sequence of numbers.

Example:

for i in range(1, 6):
    print(i)

This will print numbers from 1 to 5.