Python if-else Statement – Simple Explanation with Examples

The if-else statement is used in Python to make decisions in a program. It allows a program to choose between two different actions depending on whether a condition is True or False.

For example, suppose we want to check whether a student has passed an examination. If the marks are greater than or equal to 40, we can display “Pass”. Otherwise, we can display “Fail”.

What is an if-else Statement?

The if statement checks a condition.

• If the condition is True, the statements inside the if block are executed.
• If the condition is False, the statements inside the else block are executed.

The basic syntax is:

if condition:
    statement1
    statement2
else:
    statement3
    statement4

Notice that Python uses a colon (:) after if and else.

Also, Python uses indentation to identify which statements belong to the if or else block. Unlike C and C++, Python does not require curly braces { } for this purpose.

Simple Example

x = 10

if x > 5:
    print("x is greater than 5")
else:
    print("x is not greater than 5")

Output

x is greater than 5

Here, x contains 10. Since 10 > 5 is True, the statement inside the if block is executed. The else block is skipped.

How Does if-else Work?

The execution of an if-else statement can be understood in three simple steps:

1. Python evaluates the condition.
2. If the condition is True, the if block runs.
3. If the condition is False, the else block runs.

Only one of the two blocks is executed.

Example Using Two Variables

Consider the following program:

x = 5
y = 10

if x + y > 30:
    print("Stephen Hawking")
    print("Cosmology")
else:
    print("Albert Einstein")
    print("Physics")

First, Python calculates:

x + y = 5 + 10 = 15

Then it checks:

15 > 30

This condition is False, so the else block is executed.

Output

Albert Einstein
Physics

This example also demonstrates an important Python concept: multiple statements can belong to the same block simply by giving them the same indentation.

Indentation in Python

Indentation is very important in Python.

For example:

if x > 0:
    print("Positive")
    print("Number checked")

Both print() statements are indented, so Python considers both statements to be part of the if block.

In C or C++, curly braces are commonly used:

if (condition) {
    statement1;
    statement2;
}

Python achieves the same grouping using indentation:

if condition:
    statement1
    statement2

A common convention is to use four spaces for each level of indentation.

Relational Operators with if-else

Conditions often use relational operators such as:

Operator	Meaning
= =	Equal to
!=	Not equal to
<	Less than
<=	Less than or equal to
>	Greater than
>=	Greater than or equal to

For example:

marks = 75

if marks >= 40:
    print("Pass")
else:
    print("Fail")

Since 75 >= 40 is True, the output is:

Pass

= and == Are Different

Beginners often confuse = and ==.

= is used for assignment:

x = 10

It means that the value 10 is assigned to x.

== is used for comparison:

x == 10

It checks whether the value of x is equal to 10.

For example:

x = 10

if x == 10:
    print("x is 10")

Important Points to Remember

• if is used to check a condition.
• else provides an alternative when the if condition is false.
• Use : after if and else.
• Use indentation to define a block of statements.
• Python does not need { } to define if and else blocks.
• = is used for assignment.
• == is used for comparison.
• Only one branch of an if-else statement executes.

Practice Programs

To help you practice these concepts, I have included a PDF containing the Python if-else programs used in this tutorial.

You can download the PDF, type the programs yourself, run them in Python, and experiment by changing the values and conditions. This is a good way to understand how if-else works rather than simply memorizing the syntax.

Conclusion

The if-else statement is one of the most important decision-making tools in Python. Once you understand conditions, True/False, comparison operators, and indentation, you can easily start writing programs that make decisions.

In the next step, you can learn if-elif-else, which allows a Python program to choose between more than two possibilities.

Tip for beginners: Don’t just read the programs. Type them, run them, change the values, and observe the output. That is the easiest way to learn Python.

Python if-else Programs – PDF

Want to practice the programs explained in this tutorial?
I have prepared a PDF containing all the Python programs used in this tutorial, along with examples covering if, if-else, comparison operators, expressions, multiple statements, and indentation.

Download the PDF and practice each program yourself. Try changing the values and conditions to see how the output changes.