Conditional Statements

Conditional Statements in Python

Conditional statements are used to make decisions in a program. They allow the program to execute different blocks of code based on certain conditions in Python.

if statement

it executes code only if the condition is True.

age = 18
if age >= 18:
    print("You can vote")

You can vote

if-else statement

It executes one block if condition is true, otherwise another.

age = 16
if age >= 18:
    print("Adult")
else:
    print("Minor")

Minor

if-elif-else statement

It is used when there are multiple conditions.

marks = 75
if marks >= 90:
    print("Grade A")
elif marks >= 60:
    print("Grade B")
else:
    print("Grade C")

Grade B

Nested Conditions

Nested conditions mean using an if statement inside another if.

age = 20
has_id = True
if age >= 18:
    if has_id:
        print("Entry allowed")
    else:
        print("ID required")
else:
    print("Underage")

Entry allowed

Practical Decision Making Examples

Example 1: Find if a number is even or odd number

num = 7
if num % 2 == 0:
    print("Even number")
else:
    print("Odd number")

Odd number

Example 2: Find the largest of two numbers

a = 10
b = 20
if a > b:
    print("a is greater")
else:
    print("b is greater")

b is greater

Example 3: Create a simple Login System code.

username = "admin"
password = "1234"
if username == "admin" and password == "1234":
    print("Login successful")
else:
    print("Invalid credentials")

Login successful

Example 4: Check if a number is Positive, Negative or Zero

num = -5
if num > 0:
    print("Positive")
elif num < 0:
    print("Negative")
else:
    print("Zero")

Negative