python - 为什么我在流式传输时收到“JSONDecoderError”？

Question

使用模块 WebSockets 流式传输（加密）价格数据时出现 JSONDecoderError，我正在使用多处理。我在以前的类似问题中看到，大多数情况下单引号/双引号都存在问题，但对我来说并非如此。另外，我不会立即收到此错误。有人能帮我吗？

我的代码：

主文件

def main():
    pairs = ["BTC/USDT", "ETH/USDT", "LTC/"]

    for pair in pairs:
        pairPrice = getPrice(pair)
        if mainPrice != "0":
            pass

def getPrice(pair:str):
    path = CONSTS.allPairsPath + pair.replace("/", "") + ".json" 
    try:
        with open(path) as f:
            data = json.loads(f.read())
            return [float(data["b"]), float(data["a"])]
    except FileNotFoundError:
        return "0"

if __name__ == "__main__":

    p1 = Process(target=streaming.main)
    p2 = Process(target=main)
    p1.start()
    p2.start()
    p1.join()
    p2.join()

流式传输.py

def main():
    # Import own modules
    import CONSTS
    # Import built-in modules
    import asyncio, json
    # Import extern modules
    import websockets

    async def stream():
        async with websockets.connect("wss://stream.binance.com:9443/ws/!bookTicker") as websocket:
            while True:
                data = await websocket.recv()
                data = json.loads(data)

                documentLoc = CONSTS.allPairsPath + data["s"] + ".json"
                with open(documentLoc, "w+") as f:
                    f.write(str(data).replace("'", '"')) # replace single quotes by double quotes

    loop = asyncio.get_event_loop()

    asyncio.ensure_future(stream())
    loop.run_forever()

示例 JSON 文件

{"u": 282430213, "s": "ADABTC", "b": "0.00000480", "B": "358426.00000000", "a": "0.00000481", "A": "26697.00000000"}

一段时间后（不是即时）我收到此“JSONDecoderError”错误消息：

Traceback (most recent call last):
  File "/usr/lib/python3.8/multiprocessing/process.py", line 315, in _bootstrap
    self.run()
  File "/usr/lib/python3.8/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "main.py", line 13, in main
    loop(mainPairs)
  File "main.py", line 71, in loop
    backwardsConvertPrice = getPrice(backwardsPair)[0] # Convert back to bitcoin
  File "main.py", line 87, in getPrice
    data = json.loads(f.read())
  File "/usr/lib/python3.8/json/__init__.py", line 357, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.8/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.8/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

标签： pythonjsonpython-3.x