如何正确接收 Pubsub JSON 数据？

Posted 2023-02-16

【中文标题】如何正确接收 Pubsub JSON 数据？

【英文标题】：How to correctly receive Pubsub JSON data?

【发布时间】：2021-11-11 06:06:00

【问题描述】：

我有一个带有云功能的 GCP 管道设置，可以接收 PubSub 消息。问题是每次我向云函数发布消息（一个 json 字符串）时，收到的消息与预期的有所不同。以下是我的代码：

import base64

def myfunc(event, context):
    #receive pusub data
    if 'data' in event:
          payload = base64.b64decode(event['data']).decode('utf-8')
    else:
          payload = 'No Data'

    payloadLocal ="considerIp":False,"wifiAccessPoints":[
      "macAddress":"44:48:c1:a6:f3:d0",
      "signalStrength":-54,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0,
      "macAddress":"9c:1c:12:b0:45:f1",
      "signalStrength":-43,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0,
      "macAddress":"20:a6:cd:33:6c:f4",
      "signalStrength":-32,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0]
    
    #Compare the received payload from pubsub with the local payload
    #I expect to the same payload as payloadlocal
    if payloadLocal == payload:
      print("Payload same")
    else:
      print("Payload different")

我使用 pubsub 发布的消息是：

"considerIp":False,"wifiAccessPoints":[
      "macAddress":"44:48:c1:a6:f3:d0",
      "signalStrength":-54,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0,
      "macAddress":"9c:1c:12:b0:45:f1",
      "signalStrength":-43,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0,
      "macAddress":"20:a6:cd:33:6c:f4",
      "signalStrength":-32,
      "signalToNoiseRatio":0,
      "channel":11,
      "age":0]

但是当我将 payloadlocal 与从 pubsub 消息接收到的有效负载进行比较时，它是不同的。我缺少一些愚蠢的东西。请任何人指出它。谢谢

编辑： 经过多次尝试，我找到了解决方案：

payload = base64.b64decode(event['data'])
dict_str = payload.decode("UTF-8")
payload = ast.literal_eval(dict_str)

我确信有更好的解决方案，但这对我有用。

【参考方案1】：

您正在将有效负载作为字符串加载并检查它是否等于字典。

以这种方式加载您的消息

payload = json.loads(base64.b64decode(event['data']).decode('utf-8'))

json.loads 转换字典中的字符串，如果它是一个有效的字典。

【讨论】：

感谢您的回复。但我现在收到以下错误“在 raw_decode raise JSONDecodeError("Expecting value", s, err.value) from None json.decoder.JSONDecodeError: Expecting value: line 1 column 15 (char 14)"

编辑您的问题并打印事件内容['data']