Primes game

import random
import time

from tkMessageBox import askyesno
from tkMessageBox import showinfo


def is_prime(n):
    '''
    Returns True if the given number is a prime.
    '''

    for x in xrange(2, n):
        if n % x == 0:
            return False

    return True

def get_primes():
    '''
    Returns a generator for all primes.
    '''

    i = 3
    while True:
        if is_prime(i):
            yield i

        i += 1


def main():
    '''
    Main routine.
    '''

    now = time.time()
    count = 0
    for prime in get_primes():
        no_prime = random.randint(0, 1)
        result = askyesno('Is it a prime?', prime + no_prime)
        if (no_prime and result) or (not no_prime and not result):
            showinfo(
                'Fail!',
                'You are wrong!\nYou answered %s times correct within %.2f seconds.'% (count, time.time() - now)
            )
            break

        count += 1


if __name__ == '__main__':
    main()