prime-gen.py

#!/usr/bin/env python

# consider using pypy for major speedup

primes = set()

def prime(n):
    for i in primes:
        if i <= int(n**0.5)+1 and n % i == 0:
            return False
    return True

def main():
    i = 2
    d = 1
#   while True:
    while len(primes) < 10000:
        while i < 10:
            if prime(i):
                primes.add(i)
                print i
            i += 1
        for e in [1, 3, 7, 9]:
            i = d * 10 + e
            if prime(i):
                primes.add(i)
                print i
        d += 1

if __name__ == '__main__':

    main()