python中实现定时器Timer

实现定时器最简单的办法是就是循环中间嵌time.sleep(seconds)， 这里我就不赘述了

# encoding: UTF-8
import threading
#Timer（定时器）是Thread的派生类，
#用于在指定时间后调用一个方法。
def func():
  print 'hello timer!'
timer = threading.Timer(5, func)
timer.start()

本文实例讲述了python通过线程实现定时器timer的方法。分享给大家供大家参考。具体分析如下：

这个python类实现了一个定时器效果，调用非常简单，可以让系统定时执行指定的函数

下面介绍以threading模块来实现定时器的方法。

使用前先做一个简单试验：

import threading
def sayhello():
    print "hello world"
    global t    #Notice: use global variable!
    t = threading.Timer(5.0, sayhello)
    t.start()
t = threading.Timer(5.0, sayhello)
t.start()

运行结果如下:

>python hello.py
hello world
hello world
hello world

下面是定时器类的实现：

class Timer(threading.Thread):
    """
    very simple but useless timer.
    """
    def __init__(self, seconds):
        self.runTime = seconds
        threading.Thread.__init__(self)
    def run(self):
        time.sleep(self.runTime)
        print "Buzzzz!! Time's up!"
class CountDownTimer(Timer):
    """
    a timer that can counts down the seconds.
    """
    def run(self):
        counter = self.runTime
        for sec in range(self.runTime):
            print counter
            time.sleep(1.0)
            counter -= 1
        print "Done"
class CountDownExec(CountDownTimer):
    """
    a timer that execute an action at the end of the timer run.
    """
    def __init__(self, seconds, action, args=[]):
        self.args = args
        self.action = action
        CountDownTimer.__init__(self, seconds)
    def run(self):
        CountDownTimer.run(self)
        self.action(self.args)
def myAction(args=[]):
    print "Performing my action with args:"
    print args
if __name__ == "__main__":
    t = CountDownExec(3, myAction, ["hello", "world"])
    t.start()