用Python编写简单的定时器的方法

下面介绍以threading模块来实现定时器的方法。

首先介绍一个最简单实现：

import threading

def say_sth(str):

print str

t = threading.Timer(2.0, say_sth,[str])

t.start()

if __name__ == '__main__':

timer = threading.Timer(2.0,say_sth,['i am here too.'])

timer.start()

不清楚在某些特殊应用场景下有什么缺陷否。

下面是所要介绍的定时器类的实现：

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()