Day 6 : Python Program to Check prime number

 Python Program to Check prime number

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

if num > 1:

    for i in range(2, num):

        if num % i == 0:

            print(f"{num} is not a prime number.")

            break

    else:

        print(f"{num} is a prime number.")

else:

    print(f"{num} is not a prime number.")

Code Explanation

Input

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

input(): Prompts the user to enter a number.

int(): Converts the input into an integer.

Check if the Number is Greater than 1

if num > 1:

Prime numbers must be greater than 1.

If num <= 1, it is not a prime number, and the code skips to the else block at the end.

Check Divisibility Using a Loop

for i in range(2, num):

range(2, num): Generates numbers from 2 to 

num −1

num−1 (inclusive of 2 but excluding num).

The loop iterates over potential divisors (i) to check if any of them divide num.

If Divisible by Any Number

if num % i == 0:

    print(f"{num} is not a prime number.")

    break

num % i == 0: Checks if num is divisible by i.

If num is divisible by any number in the range, it is not a prime number.

The program prints the result and exits the loop using break to avoid unnecessary checks.

 If the Loop Completes Without Finding Divisors

else:

    print(f"{num} is a prime number.")

The else block associated with the for loop executes only if the loop completes without hitting a break.

This means no divisors were found, so num is a prime number.

Handle Numbers Less Than or Equal to 1

else:

    print(f"{num} is not a prime number.")

If num <= 1, the program directly prints that the number is not prime.

#source code --> clcoding.com