Source code for langchain_core.outputs.chat_generation

from __future__ import annotations

from typing import Any, Dict, List, Literal, Union

from langchain_core.messages import BaseMessage, BaseMessageChunk
from langchain_core.outputs.generation import Generation
from langchain_core.pydantic_v1 import root_validator
from langchain_core.utils._merge import merge_dicts


[docs]class ChatGeneration(Generation): """A single chat generation output. A subclass of Generation that represents the response from a chat model that generates chat messages. The `message` attribute is a structured representation of the chat message. Most of the time, the message will be of type `AIMessage`. Users working with chat models will usually access information via either `AIMessage` (returned from runnable interfaces) or `LLMResult` (available via callbacks). """ text: str = "" """*SHOULD NOT BE SET DIRECTLY* The text contents of the output message.""" message: BaseMessage """The message output by the chat model.""" # Override type to be ChatGeneration, ignore mypy error as this is intentional type: Literal["ChatGeneration"] = "ChatGeneration" # type: ignore[assignment] """Type is used exclusively for serialization purposes.""" @root_validator(pre=False, skip_on_failure=True) def set_text(cls, values: Dict[str, Any]) -> Dict[str, Any]: """Set the text attribute to be the contents of the message. Args: values: The values of the object. Returns: The values of the object with the text attribute set. Raises: ValueError: If the message is not a string or a list. """ try: text = "" if isinstance(values["message"].content, str): text = values["message"].content # HACK: Assumes text in content blocks in OpenAI format. # Uses first text block. elif isinstance(values["message"].content, list): for block in values["message"].content: if isinstance(block, str): text = block break elif isinstance(block, dict) and "text" in block: text = block["text"] break else: pass else: pass values["text"] = text except (KeyError, AttributeError) as e: raise ValueError("Error while initializing ChatGeneration") from e return values @classmethod def get_lc_namespace(cls) -> List[str]: """Get the namespace of the langchain object.""" return ["langchain", "schema", "output"]
[docs]class ChatGenerationChunk(ChatGeneration): """ChatGeneration chunk, which can be concatenated with other ChatGeneration chunks. """ message: BaseMessageChunk """The message chunk output by the chat model.""" # Override type to be ChatGeneration, ignore mypy error as this is intentional type: Literal["ChatGenerationChunk"] = "ChatGenerationChunk" # type: ignore[assignment] """Type is used exclusively for serialization purposes.""" @classmethod def get_lc_namespace(cls) -> List[str]: """Get the namespace of the langchain object.""" return ["langchain", "schema", "output"] def __add__( self, other: Union[ChatGenerationChunk, List[ChatGenerationChunk]] ) -> ChatGenerationChunk: if isinstance(other, ChatGenerationChunk): generation_info = merge_dicts( self.generation_info or {}, other.generation_info or {}, ) return ChatGenerationChunk( message=self.message + other.message, generation_info=generation_info or None, ) elif isinstance(other, list) and all( isinstance(x, ChatGenerationChunk) for x in other ): generation_info = merge_dicts( self.generation_info or {}, *[chunk.generation_info for chunk in other if chunk.generation_info], ) return ChatGenerationChunk( message=self.message + [chunk.message for chunk in other], generation_info=generation_info or None, ) else: raise TypeError( f"unsupported operand type(s) for +: '{type(self)}' and '{type(other)}'" )