enable icmp after up apps

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import time
import os

key = True
while key :
    time.sleep(1)
    grep = os.popen ("ps -A | grep idjc")
    string = grep.readlines()
    can_find = len(string)
    if can_find == 2 :
    time.sleep(10)
        os.popen("echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all")
        key = False