Python Syntax Error with else statement

So, while I was screwing around with some Project Euler (which has really made programming interesting), I got a weird syntax error.

My code is:

import math
primes = [2,3]
mult = 1
test = -1
def isPrime(n):
    counter = 2
maxTest = math.sqrt(n)+1
nowTest = 5
while nowTest < maxTest:
    if n % nowtest == 0:
        return 0
    elif len(primes) > counter:
        counter += 1
        nowTest = primes[counter]
    else:
        nowTest += 2
return 1
while len(primes) < 10001:
    if isPrime(6 * mult + test) == 1:
        primes.append(6 * mult + test)
    elif test == -1:
        test = 1
    elif test == 1:
        mult += 1
        test = -1
    if len(primes) >= 10:
        print(primes[0:10]
    if len(primes) < 10:
        print(primes)
print(primes[10000])

The error seems to be with the:

if len(primes) < 10:

Help appreciated.

P.S. This would be for Project Euler number 7