用Python编写简单的定时器的方法

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()

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()