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)}'"
)