|
primelist = [2,3]
|
|
def is_prime(n):
|
|
for y in primes():
|
|
if not n % y: return False
|
|
if n > y * y: return True
|
|
|
|
def primes():
|
|
for n in primelist: yield n
|
|
|
|
n = primelist[-1] + 2
|
|
while True:
|
|
n += 2
|
|
for x in primelist:
|
|
if not n % x: break
|
|
if x * x > n:
|
|
primelist.append(n)
|
|
yield n
|
|
break
|