Twisted countdown loopingcall solution

from twisted.internet.task import LoopingCall

class Manager:

    def __init__(self):
        self._token = {}

    def register(self, tasks):
        if not type(tasks) is list:
            tasks = [tasks]
        for task in tasks:
            self._token[task.Name()] = LoopingCall(task.Job(), self.finalize)

    def start(self, schedule):
        if not type(schedule) is list:
            schedule = [schedule]
        for task, timer in schedule:
            self._token[task.Name()].start(timer, False)

    def finalize(self, task):
        self._token[task.Name()].stop()
        del self._token[task.Name()]
        if not self._token:
            reactor.stop()

class Countdown(object):

    def __init__(self, name, start):
        self.name = name
        self.counter = start

    def Name(self):
        return self.name

    def Job(self):
        return self.count

    def count(self, finallize=lambda x: None):
        print 'counter %s:' % str(self.name), self.counter, '...'
        if self.counter == 0:
            finallize(self)
            print 'counter %s finished!' % str(self.name)
        else:
            self.counter -= 1

mng = Manger()
cntA = Countdown('AAA', 5)
cntB = Countdown('BB', 10)
cntC = Countdown('C', 7)

mng.register(cntA)
mng.register([cntB, cntC])

mng.start([(cntA, 1), (cntB, 0.3)])
mng.start((cntC, 0.5))

from twisted.internet import reactor
reactor.run()