Why conditional statements are needed in Python

Introduction

Conditional statements help a program make choices. They let the program do different things based on different situations.

When you want to check if a number is positive or negative and act differently.

When you want to decide if a user can log in based on their password.

When you want to give a discount only if the customer buys more than 5 items.

When you want to show a message only if it is raining.

When you want to stop a game if the player loses all lives.

Syntax

Python

if condition:
    # do something
elif another_condition:
    # do something else
else:
    # do something if no conditions above are true

Use if to check the first condition.

Use elif for additional conditions.

else runs if no conditions are true.

Examples

This checks if the temperature is above 30 and prints a message.

Python

if temperature > 30:
    print("It's hot outside!")

This chooses between two messages based on age.

Python

if age >= 18:
    print("You can vote.")
else:
    print("You are too young to vote.")

This uses multiple conditions to decide the grade.

Python

if score >= 90:
    print("Grade A")
elif score >= 80:
    print("Grade B")
else:
    print("Grade C or below")

Sample Program

This program checks the temperature and prints a message based on its value.

Python

temperature = 25
if temperature > 30:
    print("It's hot outside!")
elif temperature > 20:
    print("The weather is nice.")
else:
    print("It's a bit cold.")

Important Notes

Indentation is important in Python to show which code belongs to each condition.

Conditions must be something that can be true or false.

Summary

Conditional statements let programs make decisions.

They help run different code depending on the situation.

Use if, elif, and else to handle choices.