python - Writing a function that checks prime numbers

Question

def primecheck(num): 
if num > 1:  
    for i in range(2, num): 
        if (num % i) == 0: 
            return False 
            break
        else: 
            return True

Im trying to make a function that checks if an input is prime or not. This code does return True if I enter a prime number, but it also enters true whenever I enter a multiple of a prime number? Why is this happening

thanks

Answer 1

The problem with your code is that you have return statements in the first iteration of the loop. Also break statement is not needed. Moving return True outside the loop gives the solution:

def primecheck(num):
    for i in range(2, num):
       if num % i == 0:
           return False
    return True

I leave num = 0 or 1 for you.