If–Else Conditional Statements in Python

Conditional statements in Python are used to make decisions. The program executes different blocks of code depending on whether a condition is True or False.

💡 Decision-making is one of the most important concepts in programming.

What is an if Statement?

The if statement executes a block of code only when the given condition is true. 

age = 18

if age >= 18:
    print("You are eligible to vote")

if–else Statement

The else block runs when the if condition is false. 

number = 5

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

if–elif–else Statement

Use elif (else if) to check multiple conditions. Python checks conditions from top to bottom. 

marks = 75

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

Important Rules

📌 Follow these rules to avoid errors in conditional statements.
  • Conditions must end with a colon :
  • Indentation is mandatory in Python
  • elif can be used multiple times
  • else is optional

Real-Life Example

Checking whether a student has passed an exam:

marks = 32

if marks >= 35:
    print("Pass")
else:
    print("Fail")
❌ Incorrect indentation will cause an error in Python.

Practice

  1. Check if a number is positive or negative
  2. Write a program to check even or odd
  3. Check grade based on marks
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