def prime_generator():
    potential = 2
    primes = []

    while True:
        while any(map(lambda x: potential % x == 0, primes)):
            potential += 1

        yield potential
        primes.append(potential)

prime_numbers = prime_generator()
known_primes = [2, 3, 5, 7, 11, 13, 17, 19, 23]

for n in known_primes:
    assert prime_numbers.next() == n, n