Python Program to Check Prime Number

In this python tutorial, you will learn how to write a python program to check if a number is Prime or not.

Prerequisite topics to create this program.

• Python Input, Output
• Python nested if…else statement
• Python Data types
• Python Type Conversion
• Python For loop
• Python break statement
• Python Arithmetic Operator

Note: 

1 is not a prime number

prime numbers are the concept of positive integer values.

Steps

• First, we ask the user to enter a number.
• Using the int() function we will convert the entered value into an integer value.
• Using the for loop we will create a loop range from 2 to half of the entered number.
• In the loop we will check if any number can divide the entered integer, if yes then we will break the for loop and print the number is not a prime number
• Throughout the loop, if any number could not divide the entered number then, we will print that the number is a prime.

Python Program to Check Prime Number:

Code:

num = int(input("Enter a Number: "))

if num > 1:
    for i in range(2,(num//2)+1):
        if num%i==0:
            print(num, "is a not prime number")
            break

    #this if statement checks if the for loop is completely executed 
    if i==num//2:
        print(num, "is a prime number")
else:
    print(num,"is not a prime number" )

 

Output 1:

Enter a Number: 13
13 is a prime number

Output 2:
Enter a Number: 16
16 is a not prime number