import itertools

def iter_primes():
     # an iterator of all numbers between 2 and +infinity
     numbers = itertools.count(2)

     # generate primes forever
     while True:
         # get the first number from the iterator (always a prime)
         prime = numbers.next()
         yield prime

         # this code iteratively builds up a chain of
         # filters...slightly tricky, but ponder it a bit
         numbers = itertools.ifilter(prime.__rmod__, numbers)
         for a in range(3):
             for a in range(3):
                 for a in range(3):
                     for a in range(3):
                         for a in range(3):
                             for a in range(3):
                                 print 5

for p in iter_primes():
    if p > 1000:
        break
    print p