asyncio python 3.6 代码到 asyncio python 3.4 代码答案

【问题标题】：asyncio python 3.6 code to asyncio python 3.4 codeasyncio python 3.6 代码到 asyncio python 3.4 代码
【发布时间】：2018-02-10 11:46:54
【问题描述】：

我有这个 3.6 异步代码：

async def send(command,userPath,token):
    async with websockets.connect('wss://127.0.0.1:7000',ssl=ssl.SSLContext(protocol=ssl.PROTOCOL_TLS)) as websocket:
        data = json.dumps({"api_command":"session","body":command,"headers": {'X-User-Path': userPath, 'X-User-Token': token}})
        await websocket.send(data)
        response = await websocket.recv()
        response = json.loads(response)
        if 'command' in response:
            if response['command'] == 'ACK_COMMAND' or response['command'] == 'ACK_INITIALIZATION':
                return (response['message'],200)
        else:
            return(response,400)

我转换成这个 3.4 异步代码

@asyncio.coroutine
def send(command,userPath,token):
    with websockets.connect('wss://127.0.0.1:7000',ssl=ssl.SSLContext(protocol=ssl.PROTOCOL_TLS)) as websocket:
        data = json.dumps({"api_command":"session","body":command,"headers": {'X-User-Path': userPath, 'X-User-Token': token}})
        yield from websocket.send(data)
        response = yield from websocket.recv()
        response = json.loads(response)
        if 'command' in response:
            if response['command'] == 'ACK_COMMAND' or response['command'] == 'ACK_INITIALIZATION':
                return (response['message'],200)
        else:
            return(response,400)

虽然解释器运行转换，但当我调用该函数时会出现此错误：

with websockets.connect('wss://127.0.0.1:7000',ssl=ssl.SSLContext(protocol=ssl.PROTOCOL_TLS)) as websocket:
AttributeError: __enter__

我觉得有更多的东西要转换，但我不知道是什么。如何使 3.4 代码工作？

注意：我使用 3.6 python 运行 3.4 代码

【问题讨论】：

async with 不能被普通的with 替换。另见stackoverflow.com/questions/37465816/async-with-in-python-3-4

标签： python python-asyncio

【解决方案1】：

可以在async with websockets.connect 中找到here，您应该这样做：

websocket = yield from websockets.connect('ws://localhost:8765/')
try:
    # your stuff
finally:
    yield from websocket.close()

在你的情况下是：

@asyncio.coroutine
def send(command,userPath,token):
    websocket = yield from websockets.connect('wss://127.0.0.1:7000',ssl=ssl.SSLContext(protocol=ssl.PROTOCOL_TLS))
    try:
        data = json.dumps({"api_command":"session","body":command,"headers": {'X-User-Path': userPath, 'X-User-Token': token}})
        yield from websocket.send(data)
        response = yield from websocket.recv()
        response = json.loads(response)
        if 'command' in response:
            if response['command'] == 'ACK_COMMAND' or response['command'] == 'ACK_INITIALIZATION':
                return (response['message'],200)
        else:
            return(response,400)
    finally:
        yield from websocket.close()

【讨论】：