LoopingCallCountdown.py

from twisted.internet.task import LoopingCall
from twisted.internet import reactor

''' LJ: Runs three different countdown objects using LoopingCall, each obj has different countdown interval.
    Used Python 2.6.1 and Twisted 11.1.0
 '''

class Countdown(object):
    #Initialize counter for particular countdown object
    def __init__(self, countdowns, index):
        self.counter = countdowns[index]

    #Performs the countdown until zero, decrements from the Countdowns toFinish counter.
    #When countdowns toFinish reach zero, then we stop the reactor.
    def count(self):
        if self.counter:
            print self.counter, "..."
            self.counter -= 1
            if self.counter == 0:
                self.loopCall.stop()
                global toFinish
                toFinish -= 1
                if toFinish == 0:
                    reactor.stop()


print 'Start!'

#Below is a list of different countdowns we want to perform
countdowns =[5,11,3]
toFinish = len(countdowns)

#initialise basic countdown objects. Make sure this matches number found the countdowns array.
countdown1 = Countdown(countdowns, 0)
countdown2 = Countdown(countdowns, 1)
countdown3 = Countdown(countdowns, 2)

#assign the loopingCall Object - must have separate line to start since start() returns a deferred.
countdown1.loopCall = LoopingCall(countdown1.count)
countdown1.loopCall.start(0.8)
countdown2.loopCall = LoopingCall(countdown2.count)
countdown2.loopCall.start(1.0)
countdown3.loopCall = LoopingCall(countdown3.count)
countdown3.loopCall.start(0.1)

reactor.run()
print 'Stop!'