Python If Else

Python If Else statement is used to conditionally choose between if block and else block for execution.

If the condition evaluates to True, then interpreter executes if-block. But, if the condition evaluates to False, then interpreter executes else-block.

In this tutorial, we will learn the syntax of if-else statement, how to write an if-else statement with a condition, with the help of example Python programs.

Syntax

The syntax of if-else statement is

if <condition>:
    statement(s)
else:
    statement(s)

where condition could be an expression that evaluates to a boolean value.

When interpreter enter if-else statement, it first evaluates the condition. If condition is True, statement(s) inside if block execute, or if condition is False, statements(s) inside else block execute.

Flowchart

The working of if-else statement in Python is shown in the following picture.

Python If Else Flowchart

Examples

Check if Number is Even or Odd

In the following program, we write an if-else statement where the condition checks if given number is even.

Example.py

n = 4

if n%2 == 0:
    print(f'{n} is even number.')
else:
    print(f'{n} is odd number.')
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Output

4 is even number.

Note : Observe the indentation and alignment of the statements inside the if-block and else-block. Unlike programming languages like Java or C programming, where the statements are enclosed in curly braces, Python considers the alignment of statements as block representation.

Now, let us take a value for n, such that the condition becomes false.

Example.py

n = 3

if n%2 == 0:
    print(f'{n} is even number.')
else:
    print(f'{n} is odd number.')
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Output

3 is odd number.

Since we have taken a value for n such that the condition n%2 == 0 becomes False, the statement(s) inside else block were executed.

Choose a Car

In the following program, we write an if-else statement to choose a car based on the money we have to spend.

Example.py

money = 125000

if money > 100000:
    print("Buy Premium Car.")
else:
    print("Buy Budget Car.")
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Output

Buy Premium Car.

Conclusion

In this Python Tutorial, we have learnt if-else conditional statement, and how any statement in if or else block could be another if or if-else conditional statements.