python只允许启动一个实例的代码

python_self_lock.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Created by edsion on 2017/3/10

import fcntl, sys, time, os

pidfile = 0


def ApplicationInstance():
    global pidfile
    pidfile = open(os.path.realpath(__file__), "r")
    try:
        fcntl.flock(pidfile, fcntl.LOCK_EX | fcntl.LOCK_NB)  # 创建一个排他锁,并且所被锁住其他进程不会阻塞
    except:
        print("another instance is running...")
        sys.exit(1)


if __name__ == "__main__":
    ApplicationInstance()
    while True:
        print('running...')
        time.sleep(1)