33 not factorizable?

hi! in the description of exercise checkio(33)=0 , but i made a algorithm that factor 33 into 3x11...

def is_prime(num):
    count=0
    for i in range(1,num+1):
        if (num % i) == 0:
            count += 1
    if (count == 2):
        return True
    else:
        return False

def get_lower_primes(num):
    lowers=[]
    for i in range(1,num):
        if is_prime(i):
            lowers.append(i)
    return lowers

def factor(num):
    #returns array of factor of a num
    fac=[]
    primes=get_lower_primes(num)
    for i in range(len(primes)):
        while (num % primes[i])==0:
            fac.append(primes[i])
            num = num // primes[i]
    print fac

factor(33)

and returns [3, 11] I try to locate the error, but i couldn't, any help would be apreciatted ...