我已经设法导入/安装了 Twisted 的asyncioreactor并执行了一个微不足道的异步函数：
from twisted.internet import asyncioreactor
asyncioreactor.install()
from twisted.internet import task
from twisted.internet.defer import inlineCallbacks
from twisted.internet.defer import ensureDeferred
async def sleepy(reactor):
print("SLEEPING")
await task.deferLater(reactor, 3.0, lambda: None)
print("done sleep")
return 42
@task.react
def main(reactor):
d = ensureDeferred(sleepy(reactor))
d.addCallback(print)
return d
我想在所述代码中混合一个异步库，例如asyncio.sleep. 我尝试了以下方法：
from twisted.internet import asyncioreactor
asyncioreactor.install()
from twisted.internet import task
from twisted.internet.defer import inlineCallbacks
from twisted.internet.defer import ensureDeferred
import asyncio
async def sleepy(reactor):
print("SLEEPING")
await asyncio.sleep(3)
print("done sleep")
return 42
@task.react
def main(reactor):
d = ensureDeferred(sleepy(reactor))
d.addCallback(print)
return d
这将产生以下错误：
$ python test.py
SLEEPING
main function encountered error
Traceback (most recent call last):
File "test.py", line 16, in <module>
@task.react
File "/Users/blz/.pyenv/versions/3.6.0/lib/python3.6/site-packages/twisted/internet/task.py", line 908, in react
finished = main(_reactor, *argv)
File "test.py", line 18, in main
d = ensureDeferred(sleepy(reactor))
File "/Users/blz/.pyenv/versions/3.6.0/lib/python3.6/site-packages/twisted/internet/defer.py", line 823, in ensureDeferred
return _inlineCallbacks(None, coro, Deferred())
--- <exception caught here> ---
File "/Users/blz/.pyenv/versions/3.6.0/lib/python3.6/site-packages/twisted/internet/defer.py", line 1301, in _inlineCallbacks
result = g.send(result)
File "test.py", line 11, in sleepy
await asyncio.sleep(3)
File "/Users/blz/.pyenv/versions/3.6.0/lib/python3.6/asyncio/tasks.py", line 476, in sleep
return (yield from future)
builtins.AssertionError: yield from wasn't used with future
很公平，我想，所以我尝试用await ensureDeferred(asyncio.sleep(3))和await asyncio.ensure_future(asyncio.sleep(3))交换await asyncio.sleep(3)，但我得到完全相同的错误。
如何安排 aio 协程(和/或Future)在与asyncioreactor相同的事件循环上运行？
所以我尝试将 await asyncio.sleep(3) 与 await 交换 ensureDeferred(asyncio.sleep(3)) and await asyncio.ensure_future(asyncio.sleep(3))
你快到了，你应该将两者结合起来，并使用Deferred.fromFuture而不是ensureDeferred：
await Deferred.fromFuture(asyncio.ensure_future(asyncio.sleep(3)))
规则是，在扭曲上下文中运行的async def函数(带有ensureDeferred)只能在Deferred上等待，而在异步上下文中运行的async def函数(带有ensure_future)只能在异步Future上(始终可以等待其他协程对象(async def函数调用的结果)，但链最终会导致Deferred/Future)。要从异步Future转换为Deferred请使用Deferred.fromFuture，并转换为异步Future使用Deferred.asFuture。
可以将上下文从一个切换到另一个上下文，然后再切换回来。在这个(人为的)示例中，我们从运行sleepy_twisted开始 扭曲上下文，执行扭曲睡眠，然后切换到异步上下文以运行sleepy_asyncio执行异步睡眠，但随后再次切换到扭曲睡眠的扭曲上下文：
from twisted.internet import asyncioreactor, task
from twisted.internet.defer import inlineCallbacks, ensureDeferred, Deferred
import asyncio
asyncioreactor.install()
async def sleepy_asyncio(reactor):
print("Sleep 2")
await asyncio.sleep(1)
print("Sleep 3")
await Deferred.asFuture(task.deferLater(reactor, 1, lambda: None), loop=asyncio.get_running_loop())
async def sleepy_twisted(reactor):
print("Sleep 1")
await task.deferLater(reactor, 1, lambda: None)
await Deferred.fromFuture(asyncio.ensure_future(sleepy_asyncio(reactor)))
print("done")
@task.react
def main(reactor):
return ensureDeferred(sleepy_twisted(reactor))
哇，你遇到了一个有趣的角落案例！ 通过使用 asyncio.sleep()，你触发了一些有趣的行为。
我想你可能已经发现了一个错误 Twisted 与 Python 3 异步反应器和 async/await 的集成。 您可能希望跟进 Twisted 邮件列表中的 Twisted 开发人员。
我不是100%确定，但这是我的想法。
asyncio.sleep() 的实现与 Python 3 紧密耦合。 异步实现。 它使用异步。future(类似于 Twisted 的 deferred)，它使用 get_event_loop()(类似于 Twisted 的反应堆)。
asyncio.sleep 是这样实现的：
@coroutine
def sleep(delay, result=None, *, loop=None):
"""Coroutine that completes after a given time (in seconds)."""
if delay == 0:
yield
return result
if loop is None:
loop = events.get_event_loop()
future = loop.create_future()
h = future._loop.call_later(delay,
futures._set_result_unless_cancelled,
future, result)
try:
return (yield from future)
finally:
h.cancel()
我稍微更改了您的代码示例以通过 Twisted 的 asyncioreactor 事件循环到 asyncio.sleep()：
from twisted.internet import asyncioreactor
asyncioreactor.install()
from twisted.internet import reactor
from twisted.internet import task
from twisted.internet.defer import inlineCallbacks
from twisted.internet.defer import ensureDeferred
import asyncio
async def sleepy(reactor):
print("SLEEPING")
await asyncio.sleep(3, loop=reactor._asyncioEventloop)
print("done sleep")
return 42
@task.react
def main(reactor):
d = ensureDeferred(sleepy(reactor))
d.addCallback(print)
return d
我仍然遇到与您相同的错误：内置。断言错误：来自的收益未与将来一起使用
堆栈跟踪如下所示：
main function encountered error
Traceback (most recent call last):
File "b.py", line 16, in <module>
@task.react
File "/Users/crodrigues/twisted8/src/twisted/internet/task.py", line 908, in react
finished = main(_reactor, *argv)
File "b.py", line 19, in main
d = ensureDeferred(sleepy(reactor))
File "/Users/crodrigues/twisted8/src/twisted/internet/defer.py", line 823, in ensureDeferred
return _inlineCallbacks(None, coro, Deferred())
--- <exception caught here> ---
File "/Users/crodrigues/twisted8/src/twisted/internet/defer.py", line 1301, in _inlineCallbacks
result = g.send(result)
File "b.py", line 12, in sleepy
await asyncio.sleep(3, loop=reactor._asyncioEventloop)
File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/asyncio/tasks.py", line 478, in sleep
return (yield from future)
builtins.AssertionError: yield from wasn't used with future
我认为 asyncio.sleep() 是一个应该运行到完成的协程 在 Asyncio 循环中，但这在这里没有发生，因此断言。
我认为问题是由结果 = g.send(result)引入的。 我不确定您是否可以将send()发送到这样的协程并期望它正常工作。
我建议您在扭曲的邮件列表中询问以获得更详细的反馈。