python中使用websocket进行链接与数据存储

2023-10-31 14:26:02 浏览数 (2)

笔者最近在测试星火大模型的时候，他们是使用websocket 来建立对话，而且星火大模型开放的测试代码，质量上不咋地（20231030记录），还需要对websocket有一定的了解，才适合自己微调。

安装：

代码语言：javascript复制
pip install websocket
pip install websocket-client

1 常见的websocket获取数据的方法

参考【python: websocket获取实时数据的几种常见链接方式】常见的两种。

1.1 第一种使用create_connection链接

需要pip install websocket-client (此方法不建议使用，链接不稳定，容易断，并且连接很耗时)

代码语言：javascript复制
import time
from websocket import create_connection

url = 'wss://i.cg.net/wi/ws'
while True:  # 一直链接，直到连接上就退出循环
    time.sleep(2)
    try:
        ws = create_connection(url)
        print(ws)
        break
    except Exception as e:
        print('连接异常：', e)
        continue
while True:  # 连接上，退出第一个循环之后，此循环用于一直获取数据
    ws.send('{"event":"subscribe", "channel":"btc_usdt.ticker"}')
    response = ws.recv()
    print(response)

1.2 第二种：WebSocketApp run_forever的方式

代码语言：javascript复制
import websocket


def on_message(ws, message):  # 服务器有数据更新时，主动推送过来的数据
    print(message)


def on_error(ws, error):  # 程序报错时，就会触发on_error事件
    print(error)


def on_close(ws):
    print("Connection closed ……")


def on_open(ws):  # 连接到服务器之后就会触发on_open事件，这里用于send数据
    req = '{"event":"subscribe", "channel":"btc_usdt.deep"}'
    print(req)
    ws.send(req)


if __name__ == "__main__":
    websocket.enableTrace(True)
    ws = websocket.WebSocketApp("wss://i.cg.net/wi/ws",
                                on_message=on_message,
                                on_error=on_error,
                                on_close=on_close)
    ws.on_open = on_open
    ws.run_forever(ping_timeout=30)

第二种方式里面，run_forever其实是流式返回内容，大概可以看，流式输出的样例：

代码语言：javascript复制
{"code":0,"sid":"5ebc0d6833b54909b4a51fbe75a5051a","status":0}
### error: 'content'

{"code":0,"fileRefer":"{"43816997a7a44a299d0bfb7c360c5838":[2,0,1]}","sid":"5ebc0d6833b54909b4a51fbe75a5051a","status":99}
### error: 'content'

{"code":0,"content":"橘","sid":"5ebc0d6833b54909b4a51fbe75a5051a","status":1}

橘{"code":0,"content":"子。","sid":"5ebc0d6833b54909b4a51fbe75a5051a","status":1}

子。{"code":0,"content":"","sid":"5ebc0d6833b54909b4a51fbe75a5051a","status":2}
### closed ###

那么run_forever流式输出，正常的内容如何保存呢，进入下一章

2 针对run_forever内容保存

2.1 通过定义global变量来保存内容

参考【将Websocket数据保存到Pandas】 来看一下，文中的案例：

代码语言：javascript复制
import json

import pandas as pd
import websocket

df = pd.DataFrame(columns=['foreignNotional', 'grossValue', 'homeNotional', 'price', 'side',
                           'size', 'symbol', 'tickDirection', 'timestamp', 'trdMatchID'])


def on_message(ws, message):
    msg = json.loads(message)
    print(msg)
    global df
    # `ignore_index=True` has to be provided, otherwise you'll get
    # "Can only append a Series if ignore_index=True or if the Series has a name" errors
    df = df.append(msg, ignore_index=True)


def on_error(ws, error):
    print(error)


def on_close(ws):
    print("### closed ###")


def on_open(ws):
    return


if __name__ == "__main__":
    ws = websocket.WebSocketApp("wss://www.bitmex.com/realtime?subscribe=trade:XBTUSD",
                                on_open=on_open, on_message=on_message, on_error=on_error, on_close=on_close)
    ws.run_forever()

其中global df是在定义全局变量df，可以在函数中把流式数据拿出来，还是很不错的

2.2 通过CallbackToIterator()来返回

在开源项目中ChuanhuChatGPT，看到了使用的方式spark.py，个人还没有尝试，只是贴在这里。

贴一下这个函数：

代码语言：javascript复制
class CallbackToIterator:
    def __init__(self):
        self.queue = deque()
        self.cond = Condition()
        self.finished = False

    def callback(self, result):
        with self.cond:
            self.queue.append(result)
            self.cond.notify()  # Wake up the generator.

    def __iter__(self):
        return self

    def __next__(self):
        with self.cond:
            # Wait for a value to be added to the queue.
            while not self.queue and not self.finished:
                self.cond.wait()
            if not self.queue:
                raise StopIteration()
            return self.queue.popleft()

    def finish(self):
        with self.cond:
            self.finished = True
            self.cond.notify()  # Wake up the generator if it's waiting.


# 主函数截取
def get_answer_stream_iter(self):
    wsParam = Ws_Param(self.appid, self.api_key, self.api_secret, self.spark_url)
    websocket.enableTrace(False)
    wsUrl = wsParam.create_url()
    ws = websocket.WebSocketApp(
        wsUrl,
        on_message=self.on_message,
        on_error=self.on_error,
        on_close=self.on_close,
        on_open=self.on_open,
    )
    ws.appid = self.appid
    ws.domain = self.domain

    # Initialize the CallbackToIterator
    ws.iterator = CallbackToIterator()

    # Start the WebSocket connection in a separate thread
    thread.start_new_thread(
        ws.run_forever, (), {"sslopt": {"cert_reqs": ssl.CERT_NONE}}
    )

    # Iterate over the CallbackToIterator instance
    answer = ""
    total_tokens = 0
    for message in ws.iterator:
        data = json.loads(message)
        code = data["header"]["code"]
        if code != 0:
            ws.close()
            raise Exception(f"请求错误: {code}, {data}")
        else:
            choices = data["payload"]["choices"]
            status = choices["status"]
            content = choices["text"][0]["content"]
            if "usage" in data["payload"]:
                total_tokens = data["payload"]["usage"]["text"]["total_tokens"]
            answer  = content
            if status == 2:
                ws.iterator.finish()  # Finish the iterator when the status is 2
                ws.close()
            yield answer, total_tokens

截取了部分代码，这里先是定义ws.iterator = CallbackToIterator()然后通过迭代从for message in ws.iterator:拿出数据，看上去也是可行的

python websocket 连接 数据 数据存储

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