Python: Random IP

I’m not very experienced with python, but I occasionally program with some help from a friend. This script generates random ip addresses and tries to connect to them, displaying the addresses that work:

import socket
from random import randint

def randip():
    while True:
        yield ".".join(str(randint(1, 255)) for i in range(4))

a = []
for address in randip():
        try:
                s = socket.socket()
                s.settimeout(0.3)
                s.connect((address, 80))
                print address, "WORKS!!!"
                a.append(address)
        except socket.error:
                if len(a) != 5:
                        continue
                else:
                        print a
                        raw_input("press enter")
                        break