使用Datastore API报错Expected a message object原因排查

参考Datastore API官方文档编写Python操作代码，具体实现如下：

from google.cloud import datastore

class DatastoreConf:
    def __init__(self):
        self.datastore_client = datastore.Client()

    def insert_entity(self):
        complete_key = self.datastore_client.key("Task", "sampleTask")
        task = datastore.Entity(key=complete_key)
        task.update(
            {
                "category": "Personal",
                "done": False,
                "priority": 4,
                "description": "Learn Cloud Datastore",
            }
        )
        self.datastore_client.put(task)

d = DatastoreConf()
d.insert_entity()

已正确配置GOOGLE_APPLICATION_CREDENTIALS环境变量指向服务账号密钥，所用账号具备足够操作权限，运行时抛出错误：
TypeError: Expected a message object, but got kind: "Task" name: "sampleTask"

完整报错追踪栈：

Traceback (most recent call last):
  File "C:/Users/user/project/datastore_configuration.py", line 24, in <module>
    d.get_entity()
  File "C:/Users/user/project/datastore_configuration.py", line 21, in get_entity 
    self.datastore_client.put(task) 
  File "C:\Users\user\project\venv\lib\site-packages\google\cloud\datastore\client.py", line 575, in put
    self.put_multi(entities=[entity], retry=retry, timeout=timeout) 
  File "C:\Users\user\projectvenv\lib\site-packages\google\cloud\datastore\client.py", line 612, in put_multi 
    current.put(entity) 
  File "C:\Users\user\project\venv\lib\site-packages\google\cloud\datastore\batch.py", line 227, in put 
    _assign_entity_to_pb(entity_pb, entity) 
  File "C:\Users\user\project\venv\lib\site-packages\google\cloud\datastore\batch.py", line 373, in _assign_entity_to_pb 
    bare_entity_pb = helpers.entity_to_protobuf(entity) 
  File "C:\Users\user\project\venv\lib\site-packages\google\cloud\datastore\helpers.py", line 207, in entity_to_protobuf 
    key_pb = entity.key.to_protobuf() 
  File "C:\Users\user\project\venv\lib\site-packages\google\cloud\datastore\key.py", line 298, in to_protobuf 
    key.path.append(element)

依赖版本不兼容。当前环境中google-cloud-datastore和其依赖的protobuf、google-api-core版本不匹配，Key对象序列化为protobuf格式时，路径元素没有被正确封装为要求的PathElement消息实例，直接传入了原始键属性对象，触发protobuf类型校验错误。
常见触发场景：

• 单独升级google-cloud-datastore时未同步更新关联依赖
• 虚拟环境内其他谷歌云相关库强制安装了不兼容的低版本protobuf或google-api-core

• 卸载当前存在冲突的相关包：

pip uninstall -y google-cloud-datastore protobuf google-api-core

• 重新安装稳定版google-cloud-datastore，安装过程会自动拉取版本匹配的依赖：

pip install google-cloud-datastore

• 若需要固定版本避免后续冲突，可使用经过兼容性验证的版本组合：google-cloud-datastore==2.15.2 + protobuf>=3.19.5,<5.0.0dev
• 安装完成后执行pip list | grep -E "google-cloud-datastore|protobuf|google-api-core"校验版本，确认无版本冲突后重新运行代码即可。

内容的提问来源于stack exchange，提问作者crowlek