python subProcess problem

proc.py

# coding: utf8

from multiprocessing import Process
import os
import time
import setproctitle


setproctitle.setproctitle('subprocess')
def targ(x):
    setproctitle.setproctitle('subprocess_' + str(x))
    print '这是一个进程任务' + str(os.getpid())
    while 1:
        time.sleep(0.5)

processes = {}

def createProc(x):
    process = Process(target=targ, args=(x,))
    process.start()

    processes[process.pid] = x

for x in range(2):
    createProc(x)


for pid, x in processes.iteritems():

    pid, status = os.wait()

    del processes[pid]

    createProc(x)