Socket.io客户端连接服务器触发AttributeError错误求助

错误详情 #

Client connected:  3uRG6PtVuta3wHsbAAAD
message async handler error
Traceback (most recent call last):
  File "/home/ahmed/.local/lib/python3.10/site-packages/engineio/async_server.py", line 483, in run_async_handler
    return await self.handlers[event](*args)
  File "/home/ahmed/.local/lib/python3.10/site-packages/socketio/async_server.py", line 669, in _handle_eio_message
    await self._handle_connect(eio_sid, pkt.namespace, pkt.data)
  File "/home/ahmed/.local/lib/python3.10/site-packages/socketio/async_server.py", line 552, in _handle_connect
    success = await self._trigger_event(
  File "/home/ahmed/.local/lib/python3.10/site-packages/socketio/async_server.py", line 638, in _trigger_event
    ret = handler(*args)
  File "/home/ahmed/PycharmProjects/decimal-trade/prices.py", line 27, in connect
    if not thread.is_alive():
AttributeError: '_asyncio.Task' object has no attribute 'is_alive'

问题根源 #

1. 你初始化了thread = Thread()，但sio.start_background_task()在异步模式下返回的是asyncio.Task对象，而非Thread实例，因此调用is_alive()会触发属性错误。
2. 同步的requests.get()会阻塞异步事件循环，拖慢服务器响应速度。
3. 异步Socket.io服务器的事件处理器（如connect）需定义为异步函数（async def），同步函数会导致调用逻辑冲突。

修复方案 #

修改后的服务器代码 #

from aiohttp import web, ClientSession
import socketio

sio = socketio.AsyncServer(async_mode='aiohttp', logger=True, engineio_logger=True, cors_allowed_origins='*')
app = web.Application()
sio.attach(app)

# 初始化为None，替代原Thread对象
price_task = None
url = 'https://financialmodelingprep.com/api/v3/stock/real-time-price?apikey=yfmtiz4PGwIlCalGtRjsLcrQ9rF6NAHt'

async def server(request):
    return web.Response(text='Server Running...')

async def getPrices():
    async with ClientSession() as session:
        while True:
            # 用异步HTTP请求替代同步requests
            async with session.get(url) as resp:
                data = await resp.json()
                data = data['stockList']
                await sio.emit('stocks', {'data': data}, namespace='/prices')
                await sio.sleep(60)

# 将connect处理器改为异步函数
@sio.on('connect', namespace='/prices')
async def connect(sid, environ):
    global price_task
    print('Client connected: ', sid)
    # 判断异步任务是否未启动或已完成
    if price_task is None or price_task.done():
        price_task = sio.start_background_task(getPrices)

@sio.on('disconnect', namespace='/prices')
def disconnect(sid):
    print('Client disconnected: ', sid)

app.router.add_static('/static', 'static')
app.router.add_get('/', server)

if __name__ == '__main__':
    web.run_app(app, host='127.0.0.1', port=8080)

关键修改点 #

1. 异步HTTP请求：用aiohttp.ClientSession替代同步requests，避免阻塞事件循环。
2. 任务类型修正：将thread变量改为price_task，初始化为None，不再依赖Thread对象。
3. 异步事件处理器：把connect函数改为async def，适配异步Socket.io服务器的调用逻辑。
4. 任务状态判断：用price_task is None or price_task.done()替代is_alive()，正确判断异步任务的运行状态。

React端代码 #

无需修改，保持原代码即可：

import { io } from 'socket.io-client';

const URL_ = 'http://127.0.0.1:8080/prices';

export const socket = io.connect(URL_, {
    cors: {
        origin: 'http://127.0.0.1:8080',
        credentials: true,
    }
});

内容的提问来源于stack exchange，提问作者Ahmed B