功能描述

为这个类添加一个可选的id参数，可以传入或者默认设置：
'''
class ChatMessage(BaseModel):
"""聊天消息."""

role: MessageRole = MessageRole.USER
content: Optional[Any] = ""
additional_kwargs: dict = Field(default_factory=dict)

def __str__(self) -> str:
    return f"{self.role.value}: {self.content}"

@classmethod
def from_str(
    cls,
    content: str,
    role: Union[MessageRole, str] = MessageRole.USER,
    **kwargs: Any,
) -> "ChatMessage":
    if isinstance(role, str):
        role = MessageRole(role)
    return cls(role=role, content=content, **kwargs)

def _recursive_serialization(self, value: Any) -> Any:
    if isinstance(value, (V1BaseModel, V2BaseModel)):
        return value.dict()
    if isinstance(value, dict):
        return {
            key: self._recursive_serialization(value)
            for key, value in value.items()
        }
    if isinstance(value, list):
        return [self._recursive_serialization(item) for item in value]
    return value

def dict(self, **kwargs: Any) -> dict:
    # ensure all additional_kwargs are serializable
    msg = super().dict(**kwargs)

    for key, value in msg.get("additional_kwargs", {}).items():
        value = self._recursive_serialization(value)
        if not isinstance(value, (str, int, float, bool, dict, list, type(None))):
            raise ValueError(
                f"Failed to serialize additional_kwargs value: {value}"
            )
        msg["additional_kwargs"][key] = value

    return msg
    '''

原因

这是为了使类用户能够从内存对象中获取特定消息并在它之后迭代该消息，同时丢弃所有其他消息。就像Claude、Openai和其他聊天机器人允许迭代一样。

功能价值

这对于允许各种提示迭代非常有用。