Function is_prime

19-concurrency/primes/spinner_prime_async_nap.py:13–27

(n)

# tag::PRIME_NAP[]
async def is_prime(n):
    if n < 2:
        return False
    if n == 2:
        return True
    if n % 2 == 0:
        return False

    root = math.isqrt(n)
    for i in range(3, root + 1, 2):
        if n % i == 0:
            return False
        if i % 100_000 == 1:
            await asyncio.sleep(0)  # <1>
    return True
# end::PRIME_NAP[]