Python Nested If

A nested if statement is an if statement inside another if statement.

Nested if statements are used when you need to check multiple conditions that depend on each other.

Syntax

if condition1:
    if condition2:
        # code block

Simple Nested If Example

Example:

age = 20

if age >= 18:
    if age >= 21:
        print("Eligible")

Output:

No output is displayed because the second condition is False.

Nested If with Output

Example:

age = 25

if age >= 18:
    if age >= 21:
        print("Eligible")

Output:

Eligible

How Nested If Works

Python first checks the outer if condition.

If it is True, Python then checks the inner if condition.

Example:

x = 10

if x > 5:
    if x < 20:
        print("x is between 5 and 20")

Output:

x is between 5 and 20

Nested If Else

Example:

age = 18

if age >= 18:
    if age >= 21:
        print("Full Access")
    else:
        print("Limited Access")

Output:

Limited Access

Multiple Nested Conditions

Example:

username = "admin"
password = "1234"

if username == "admin":
    if password == "1234":
        print("Login Successful")

Output:

Login Successful

Nested If with User Roles

Example:

is_logged_in = True
is_admin = True

if is_logged_in:
    if is_admin:
        print("Admin Panel")

Output:

Admin Panel

Using Multiple Levels

Example:

number = 15

if number > 0:
    if number < 100:
        if number % 5 == 0:
            print("Valid Number")

Output:

Valid Number

Practical Example

Check student eligibility.

Example:

age = 20
marks = 80

if age >= 18:
    if marks >= 60:
        print("Admission Approved")

Output:

Admission Approved

Avoid Too Many Nested If Statements

Too many nested if statements can make code difficult to read.

Instead of:

if age >= 18:
    if age <= 60:
        print("Eligible")

You can write:

if age >= 18 and age <= 60:
    print("Eligible")

Output:

Eligible

Common Mistake

Incorrect indentation:

if True:
print("Hello")

Output:

IndentationError: expected an indented block

Correct:

if True:
    print("Hello")

Summary

• A nested if is an if statement inside another if.
• The inner if runs only if the outer if condition is True.
• Nested if statements are useful for checking dependent conditions.
• Proper indentation is required.
• Avoid excessive nesting when logical operators can simplify the code.