Nested Conditions

Sometimes one decision leads to another decision.

This means you may need an if statement inside another if statement.

This is called a nested condition.

What Is a Nested Condition?

A nested condition is when one condition is placed inside another condition.

Python checks the first condition first.

If it is true, then Python checks the next condition inside it.

Example

age = 20
has_id = True

if age >= 18:
    if has_id:
        print("You may enter")

How It Works

Let’s break it down:

• First, Python checks if age is 18 or more
• If true, it checks if the person has an ID
• If both are true, it prints the message

Why Use Nested Conditions?

Nested conditions are useful when one rule depends on another rule.

For example:

• A student must log in before viewing results
• A user must be an adult before entering
• A customer must pay before downloading a file

Using Else in Nested Conditions

age = 17
has_id = False

if age >= 18:
    if has_id:
        print("You may enter")
    else:
        print("ID required")
else:
    print("Too young")

Watch the Indentation

Nested conditions need careful indentation.

if condition1:
    if condition2:
        print("Yes")

Each level uses more spaces.

Code Along

logged_in = True
is_admin = True

if logged_in:
    if is_admin:
        print("Welcome Admin")

Mini Challenge

Build a movie entry checker.

Steps:

• Ask the user to enter their age
• Ask if they have a ticket (yes or no)
• If age is 18 or more:
  • If they have a ticket, print:
    Enjoy the movie
  • Otherwise, print:
    You need a ticket
• Otherwise, print:
  You are too young

Real World Use Case

Websites and apps use nested conditions for login systems, permissions, subscriptions, and multi-step checks.

Quiz

1. What is a nested condition?
2. What does Python check first?
3. Why is indentation important?
4. Can you use else in nested conditions?

Assignment

Create a banking checker.

• Ask if the user is logged in
• If yes, ask if they have money
• If yes, print Transaction allowed
• Otherwise, print a suitable message

Summary

You learned how nested conditions help Python make decisions inside other decisions.