Project Euler #27

euler27.py

from itertools import takewhile
from itertools import count
from math import sqrt

def isprime(n):
    for x in range(2, int(sqrt(n)) + 1):
        if n % x == 0:
            return 0
    return 1

def prime():
    primes = []
    for n in count(2):
        composite = 0
        for p in primes:
            if not n % p:
                composite = 1
                break
            elif p ** 2 > n:
                break
        if not composite:
            primes.append(n)
            yield n

print max((sum(1 for _ in
            takewhile(lambda x: isprime(x),
                (abs(n*n + a*n + b) for n in count()))), a * b)
                    for a in range(-999, 999, 2)
                        for b in takewhile(lambda x: x < 1000, prime()))[1]