__init__.py — langchain Source File

Source Code

"""Output classes.

Used to represent the output of a language model call and the output of a chat.

The top container for information is the `LLMResult` object. `LLMResult` is used by both
chat models and LLMs. This object contains the output of the language model and any
additional information that the model provider wants to return.

When invoking models via the standard runnable methods (e.g. invoke, batch, etc.):

- Chat models will return `AIMessage` objects.
- LLMs will return regular text strings.

In addition, users can access the raw output of either LLMs or chat models via
callbacks. The `on_chat_model_end` and `on_llm_end` callbacks will return an `LLMResult`
object containing the generated outputs and any additional information returned by the
model provider.

In general, if information is already available in the AIMessage object, it is
recommended to access it from there rather than from the `LLMResult` object.
"""

from typing import TYPE_CHECKING

from langchain_core._import_utils import import_attr

if TYPE_CHECKING:
    from langchain_core.outputs.chat_generation import (
        ChatGeneration,
        ChatGenerationChunk,
    )
    from langchain_core.outputs.chat_result import ChatResult
    from langchain_core.outputs.generation import Generation, GenerationChunk
    from langchain_core.outputs.llm_result import LLMResult
    from langchain_core.outputs.run_info import RunInfo

__all__ = (
    "ChatGeneration",
    "ChatGenerationChunk",
    "ChatResult",
    "Generation",
    "GenerationChunk",
    "LLMResult",
    "RunInfo",
)

_dynamic_imports = {
    "ChatGeneration": "chat_generation",
    "ChatGenerationChunk": "chat_generation",
    "ChatResult": "chat_result",
    "Generation": "generation",
    "GenerationChunk": "generation",
    "LLMResult": "llm_result",
    "RunInfo": "run_info",
}


def __getattr__(attr_name: str) -> object:
    module_name = _dynamic_imports.get(attr_name)
    result = import_attr(attr_name, module_name, __spec__.parent)
    globals()[attr_name] = result
    return result


def __dir__() -> list[str]:
    return list(__all__)