Twisted的inlineCallbacks

关于 Twisted的inlineCallbacks

简单理解

正如文档中所说inlineCallbacks可以帮助你使用看起来像有规整的顺序的函数代码去写回调函数Deferred.
如下小例子：

import sys
import time
from twisted.python import log
from twisted.internet import reactor
from twisted.internet.defer import inlineCallbacks, returnValue

log.startLogging(sys.stdout)


class Section(object):
    def __init__(self):
        self.sentence = "I'm now in Methods: "

    @inlineCallbacks
    def run(self):
        sections = ['audio', 'upload']
        for stage, name in enumerate(sections, 1):
            method = 'section_%s' % name
            result = yield getattr(self, method)()
            print(result)
            print('Now the stage: {}'.format(stage))

    @inlineCallbacks
    def section_audio(self):
        time.sleep(3)
        r = yield self.sentence + 'audio...'
        returnValue(r)

    @inlineCallbacks
    def section_upload(self):
        time.sleep(2)
        r = yield self.sentence + 'upload...'
        returnValue(r)


if __name__ == '__main__':
    s = Section()
    s.run()
    reactor.run()

如上边小例子,使用inlineCallbacks可以将twisted的任务，按照我们所写的代码顺序运行。而在使用inlineCallbacks时，需要函数返回一个生成器，所以我们使用yield。因为inlineCallbacks是把生成器变成一系列的callbacks进行执行。