Write a program that asks the user to input a positive integer and tells the user whether or not the number is a prime.

while True:
    try:
        x = int(input("Please enter a positive integer: ")) 
       
        if x < 0:
           raise ValueError
        break  
    except ValueError:
    
        print("That was not a valid positive integer. Please try again!")

 
if x == 2:
    print(x, "That is a prime")

else:
  
    for n in range(2,x): 

        if x % n == 0: 
            print("That is not prime")
     
            break  
    else:  
 
        print("That is prime")

The program will ask the user to input a postive integer. The program will output a message saying if the number is prime or not.

A prime number is a whole number greater than 1 that is only divisible by itself and 1, that is it’s only factors are 1 and the number itself.

To determine if a number greater than 1 is a prime number check if it can be divided, without a remainder, by any number between 2 and the number itself. Once you find any number at all, that divides into it without a remainder then it is not a prime number.

To verify this program was working ok I checked against a selection of prime numbers at Wikipedia.org.