Python If Statement

The Python If statement is one of the most useful decision making statements in real-time programming.

Python If statement allows the compiler to test the condition first and then, depending upon the result it will execute the statements. If the test condition is true then only statements with in the if statement block is executed.

In this article, we will show you the syntax, and how to use this Python If statement with a practical example.

Python If Syntax

The If statement in Python Programming has simple structure:

if (test condition):
        Statement 2
        Statement 3
        ………….
        ………….
        Statement n

NOTE: Once you hit the enter after semicolon, python will start the next statement with Tab space and this Tab space acts as curly braces ({ }) in other programming languages.

From the above code, If the test condition in the Python If statement is true, then the statements (Statement 1, Statement 2, Statement 3, ……., Statement n) will be executed, otherwise all these statements will be skipped. Let us see the flow chart for better understanding.

TIP: By clicking backspace you can exit from the If statement

Python If Statement Flow Chart

If the test condition is true then STATEMENT 1 is executed followed by STATEMENT N. If the condition is False then STATEMENT N is executed because it is out of the if condition block and it has nothing to do with the condition result.

Python If Statement Example

This program will check for the positive number using Python if statement. First, Please open your favorite IDLE to write Python script and here we are using Python 3.5.0.

Once you open Python IDLE, Please select the New File as shown in the below screenshot or else simply click Control + N

Once you click on the New File, new file window will be opened to write script for Python If Statement. Please add the following script in that new file

PYTHON CODE

# Example for Python If Statement

number = int(input(" Please Enter any integer Value: "))
if number >= 1:
    print(" You Have Entered Positive Integer ")

Once you are done, Click on the File Menu and select Save option as shown below

Please save the file as per your requirements

Once you save the file, Let us run the script and see by selecting Run Menu and clicking the Run Module or simply click F5

Once you click on Run Module, Our Python shell will pop up with message “Please Enter any integer Value:” . From the below screenshot you can observe that we entered 20 and it is positive integer

OUTPUT

ANALYSIS

First, we declared number variable and asks the user to enter any integer value. int() restrict the user not to enter non integer values

number = int(input(" Please Enter any integer Value: "))

If you look at the below Python if statement, If Value stored in the number variable is greater than or equal to 0 then the statement will be executed.

if number >= 1:
    print(" You Have Entered Positive Integer ")

Here we entered 20, which is greater than 0 that’s why it printed the statement inside the If statement block.

Python If Statement Example 2

In this Python if statement example we will show you, what happens to the statements outside the If block. To demonstrate this, we altered the example 1 and added following code.

PYTHON CODE

# Example for Python If Statement

number = int(input(" Please Enter any integer Value: "))
if number >= 1:
    print(" You Have Entered Positive Integer ")
print(" This Message is not coming from PYTHON IF STATEMENT")

If you observe the above Python If statement code, it is same code that we used in the first example. However, this time, we added one more print statement outside the If statement block with the message This Message is not coming from PYTHON IF STATEMENT

Let us run the Code. From the below screenshot you can observe that we entered 50, it means If condition is TRUE. So, python is displaying print statement inside the If statement and Outside the If block

Let’s try the negative values to deliberately fail the Python If condition

If condition failed here (number < 1). It print nothing from the Python If condition block so it printed only one print statement which is outside the block.

Thank You for Visiting Our Blog