##language:zh
'''
为未来安排任务(Scheduling tasks for the future)
'''

-- Jerry Marx 于 [<<DateTime(2004-09-11T02:42:25Z)>>] 最后编辑该页
<<TableOfContents>>

Let's say we want to run a task X seconds in the future. The way to do that is defined in the reactor interface twisted.internet.interfaces.IReactorTime:

我们想再x秒后执行一个任务,可以使用twisted.internet.interfaces.IReactorTime:

{{{
#!python
from twisted.internet import reactor

def f(s):
    print "this will run 3.5 seconds after it was scheduled: %s" % s

reactor.callLater(3.5, f, "hello, world")
}}}

If we want a task to run every X seconds repeatedly, we can use twisted.internet.task.LoopingCall:

如果想每x秒就重复执行一个任务,可以使用twisted.internet.task.LoopingCall:

{{{
#!python
from twisted.internet import task

def runEverySecond():
    print "a second has passed"

l = task.LoopingCall(runEverySecond)
l.start(1.0) # call every second

# l.stop() will stop the looping calls
}}}

If we want to cancel a task that we've scheduled:

如果想要取消一个已经安排的任务:

{{{
#!python
from twisted.internet import reactor

def f():
    print "I'll never run."

callID = reactor.callLater(5, f)
callID.cancel()
}}}

		翻译 -- Jerry Marx.

[[http://wiki.woodpecker.org.cn/moin.cgi/PyTwisted_2fLowLevelNetworkingEventLoop|(目录)Index]]

Version: 1.3.0