【下载文档:  python通过线程实现定时器timer的方法.txt 】

---

python通过线程实现定时器timer的方法
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()
以上代码在Python 2.5.4中运行通过
希望本文所述对大家的Python程序设计有所帮助。