Python Tutorials

Python Programs

Python If-Else Statement

Python If-Else Statement

In this tutorial, we will learn about if-else statements in Python. We will cover the basics of conditional execution using if-else statements.

What is an If-Else statement

An if-else statement is a conditional statement that executes one block of code if a specified condition is true, and another block of code if the condition is false.

Syntax

The syntax for the if-else statement in Python is:

if condition:
    # Code block to execute if condition is true
else:
    # Code block to execute if condition is false

The if-else statement evaluates the specified condition. If the condition is true, the code block inside the if statement is executed; otherwise, the code block inside the else statement is executed.

Flowchart of If Else Statement

Checking if a Number is Even or Odd

  1. Declare a variable num.
  2. Assign a value to num.
  3. Use an if-else statement to check if num is even or odd.
  4. Print a message indicating whether num is even or odd.

Python Program

num = 10
if num % 2 == 0:
    print(f'{num} is even.')
else:
    print(f'{num} is odd.')

Output

10 is even.

Checking if a String Starts with a Specific Value

  1. Declare a variable str.
  2. Assign a value to str.
  3. Use an if-else statement to check if str starts with a specific value.
  4. Print a message indicating the result of the check.

Python Program

str = 'Hello, world!'
if str.startswith('Hello'):
    print('String starts with 'Hello'.')
else:
    print('String does not start with 'Hello'.')

Output

String starts with 'Hello'.

Checking if a Number is Positive or Negative

  1. Declare a variable num.
  2. Assign a value to num.
  3. Use an if-else statement to check if num is positive or negative.
  4. Print a message indicating whether num is positive or negative.

Python Program

num = -5
if num > 0:
    print(f'{num} is positive.')
else:
    print(f'{num} is negative or zero.')

Output

-5 is negative or zero.