python 子进程超时退出

一:循环 忙等 子进程结束

import subprocess
import os
import time
tt = ‘555‘
cmd = "python /home/100003/python/mypython/sub2.py "+" 333"+" 444 "+tt
print time.time()
sub2 = subprocess.Popen(cmd, shell=True)
while 1:
    ret1 = subprocess.Popen.poll(sub2)
    if ret1 == 0:
        print sub2.pid,‘end‘
        break
    elif ret1 is None:
        print  ‘running‘
        time.sleep(1)
    else:
        print sub2.pid,‘term‘
        break
print time.time()