If Statement

Part of the Fundamentals section of Coddy's Python journey — lesson 20 of 77.

If statements allow us to execute code with conditions.

For example, let's look at the following code:

age = 20
status = "Child"
if age > 18:
	status = "Adult"
age += 1

The above code checks whether the age variable is greater than 18. If it is, it will set status to hold "Adult" string.

In the end, the code will increment age by 1 whether the age is greater than 18 or not.

To use an if statement, we need to add a colon : at the end of the if, and everything that is inside the if is indented with 4 spaces or tab:

if condition:
    code
    code
    code

If the condition is True, we will enter the code block inside the if (the indented code).

Challenge

Beginner

The variables a and b have missing values, fill them so that the code inside the if statement will be executed! (make sure the if condition is true)

At the end of the program, the value of c should be 3.

Bonus: try to find more than one solution!

Cheat sheet

If statements in Python allow conditional execution of code:

if condition:
    # Indented code block
    # Executed if condition is True

Key points:

Use a colon : after the condition
Indent the code block with 4 spaces or a tab
The indented code executes only if the condition is True

Example:

age = 20
status = "Child"
if age > 18:
    status = "Adult"
age += 1

In this example, status becomes "Adult" because age is greater than 18.

Try it yourself

a = ?
b = ?

# Don't change below this line
c = 0
if a >= b and not b < 10:
    c = 2

c += 1
print(f"c = {c}")

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction

The Language Hello World!Comments

4Operators Part 2

Logical Operators Part 1 Logical Operators Part 2 Recap - Simple Logic Logical Operators Part 3 Logical Operators Part 4

7Bill Split Calculator

Welcome Message Getting Input

Calculating The Tip And Total

Splitting The Bill

Formatted Output

10FizzBuzz with a Twist

Game Overview The FizzBuzz Function

Looping The Numbers

Adding The Twist

13Lists Advanced

List Slicing Part 1 List Slicing Part 2 Sequence Operators Membership

2Variables

Numbers String Boolean Naming Conventions Empty Variables Recap - Initialize Variables

5Decision Making

If StatementIf - Else Recap - Simple Calculator Nested If - Else

8Loops

For Loop While Loop Break Continue Recap - Factorial The Range Function Nested Loop Recap - Dynamic Input

11Lists Basics

Declaring a List Accessing List Elements Modifying Lists List Methods Recap - Product List Recap - Reversed List Tuple

14Daily Expense Tracker

Project Overview Exit The Program

3Operators Part 1

Arithmetic Operators Modulo Operator Arithmetic Shortcuts Recap - Simple Math Comparison Operators

6Basic IO

Output Output With Variables Input Cast Recap - Till 120 Recap - True or False

9Functions

Declare a Function Arguments Return Recap - Sigma Function Recap - Validation Function Default Values

12Iterating Over Sequences

Iterating Over Elements The Enumerate Function Iterating Over Strings Part 1 Iterating Over Strings Part 2

15Final Challenges

Flat Asterisk Pyramid Pattern Finder What To Buy