def test_gen_eratosthenes_number():
"""Verify the number of primes less than 200.
"""
g = primes.gen_eratosthenes()
ps = [next(g)]
while ps[-1] < 200:
ps.append(next(g))
assert len(ps[:-1]) == 46
def test_gen_eratosthenes_last():
"""Verify the largest prime number under 200.
"""
g = primes.gen_eratosthenes()
p = next(g)
p2 = next(g)
while p2 < 200:
p, p2 = p2, next(g)
assert p == 199
def test_primes():
assert primes.eratosthenes(5) == [2, 3]
g = primes.gen_eratosthenes()
assert [next(g) for _ in range(3)] == [2, 3, 5]