def newprime(n=(primes[-1]+2)):
isprime= False
while not isprime:
for prime in primes:
if n % prime == 0:
isprime = False
break
else:
isprime = True
if isprime:
primes.append(n)
f = open('primes.py', 'w')
f.write('primes = {0}'.format(str(primes)))
f.close()
yield n
n +=2
isprime = False
def sieve(topvalue):
if primes[-1] >= topvalue:
return
# list from largest determined prime to topvalue
list = range(primes[-1] + 1, topvalue + 1)
# for instance, two, removes all even numbers
for prime in primes:
index = 0
while prime * index <= topvalue:
try:
list.remove(prime * index)
except:
pass
index += 1
if len(list) > 0:
primes.append(list[0])
return sieve(topvalue)