Two functions for the price of one! First a function that returns True for prime numbers. Second, a function that takes a number and prints all the primes up to and including that number.

Prime Finder

def is_prime(number):
    if number <=1:
        return False
    else:
        for num in range(2, number):
            if (number % num == 0) and (number != num):
                return False
        return True

def  prime_finder(num):
    for number in range(2, num+1):
        if is_prime(number):
            print number