Question

背景：我正在与不和谐的客户端一起托管烧瓶服务器

flask服务器仅需要将消息从客户端传递给不和谐，以及将消息从不和谐传递给客户端。

致电loop.run_until_complete(sendMsg(request))时出现错误我在wait_for和sendMsg wait_for

中尝试了loop.run_until_complete()

我到处都是，却一无所获，因此不胜感激。

代码：

import discord
import json
import os
import asyncio
from flask import Flask, request, render_template
from async_timeout import timeout
from threading import Thread
from time import sleep

client = discord.Client()
messages = []
app = Flask(__name__)

def startClient():
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    client.run('token')


#
# Discord Events
#
@client.event
async def on_ready():
    print('Discord Client Ready')

@client.event
async def on_message(message):
    global messages
    message.append(message)


#
# Flask Stuff
#
async def sendMsg(request):
    await client.send_message(discord.Object('channel id'), request.form['message'])


@app.route("/chat/", methods=['GET', 'POST'])
def chatPage():
    global messages

    if request.method == 'GET':
        return render_template('main.html')

    elif request.method == 'POST':
        loop = asyncio.new_event_loop()
        loop.run_until_complete(sendMsg(request))
        return ''

@app.route("/chat/get", methods=['GET'])
def chatGet():
    return json.dumps(messages[int(request.args['lastMessageId']):])


# Start everything
os.environ["WERKZEUG_RUN_MAIN"] = 'true'
print('Starting discord.py client')
Thread(target=startClient).start()
print('Starting flask')
app.run(host='0.0.0.0', debug=True)

跟踪：

Traceback (most recent call last):
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 2309, in __call__
    return self.wsgi_app(environ, start_response)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 2295, in wsgi_app
    response = self.handle_exception(e)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/mnt/c/Users/SuperKooks/Documents/Coding/HTML/kindle-discord/app.py", line 51, in chatPage
    loop.run_until_complete(sendMsg(request))
  File "/usr/lib/python3.5/asyncio/base_events.py", line 387, in run_until_complete
    return future.result()
  File "/usr/lib/python3.5/asyncio/futures.py", line 274, in result
    raise self._exception
  File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
    result = coro.send(None)
  File "/mnt/c/Users/SuperKooks/Documents/Coding/HTML/kindle-discord/app.py", line 39, in sendMsg
    await client.send_message(discord.Object('382416348007104513'), request.form['message'])
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/discord/client.py", line 1152, in send_message
    data = yield from self.http.send_message(channel_id, content, guild_id=guild_id, tts=tts, embed=embed)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/discord/http.py", line 137, in request
    r = yield from self.session.request(method, url, **kwargs)
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/aiohttp/client.py", line 555, in __iter__
    resp = yield from self._coro
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/aiohttp/client.py", line 197, in _request
    with Timeout(timeout, loop=self._loop):
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/async_timeout/__init__.py", line 39, in __enter__
    return self._do_enter()
  File "/home/SuperKooks/.local/lib/python3.5/site-packages/async_timeout/__init__.py", line 76, in _do_enter
    raise RuntimeError('Timeout context manager should be used '
RuntimeError: Timeout context manager should be used inside a task

Answer 1

aiohttp.ClientSession()希望在协程内部被调用。尝试将Client()初始化程序移至任何async def函数中

Answer 2

该问题看起来可能是由以下原因引起的：

elif request.method == 'POST':
    loop = asyncio.new_event_loop()
    loop.run_until_complete(sendMsg(request))

这将创建一个新的事件循环，并在新循环中运行sendMsg(request)。但是，sendMsg会在其自己的事件循环中运行的client对象上调用方法。 sendMsg应该被提交到在另一个线程中运行客户端的现有事件循环。为此，您需要：

公开在startClient中创建的循环，例如到client_loop全局变量；
通过调用asyncio.run_coroutine_threadsafe替换loop = asyncio.new_event_loop(); loop.run_until_complete(sendMsg(request))，以将协程提交到已经在其他线程中运行的事件循环中。

提交代码如下：

elif request.method == 'POST':
    # submit the coroutine to the event loop thread
    send_fut = asyncio.run_coroutine_threadsafe(sendMsg(request), client_loop)
    # wait for the coroutine to finish
    send_fut.result()

Answer 3

我通过将所有对asyncio.run的调用替换为下面的asyncio_run来解决此问题。它为我解决了这两个错误：

RuntimeError: Timeout context manager should be used inside a task
RuntimeError: This event loop is already running

def asyncio_run(future, as_task=True):
    """
    A better implementation of `asyncio.run`.

    :param future: A future or task or call of an async method.
    :param as_task: Forces the future to be scheduled as task (needed for e.g. aiohttp).
    """

    try:
        loop = asyncio.get_running_loop()
    except RuntimeError:  # no event loop running:
        loop = asyncio.new_event_loop()
        return loop.run_until_complete(_to_task(future, as_task, loop))
    else:
        nest_asyncio.apply(loop)
        return asyncio.run(_to_task(future, as_task, loop))


def _to_task(future, as_task, loop):
    if not as_task or isinstance(future, Task):
        return future
    return loop.create_task(future)

第二个目标是能够将asyncio.run视为JS世界中的promise.resolve或来自.NET世界中的Task.Wait。

Answer 4

我知道这个问题已经有一段时间了，不过：

@app.listener("before_server_start")
async def setup_downloader(app, _):
    app.ctx.session = aiohttp.ClientSession()

感谢 kolypto 的提示

RuntimeError：任务中应使用超时上下文管理器

4 个答案: