Source code for langchain.callbacks.tracers.logging

__all__ = ["LoggingCallbackHandler"]

import logging
from typing import Any, Optional
from uuid import UUID

from langchain_core.exceptions import TracerException
from langchain_core.tracers.stdout import FunctionCallbackHandler
from langchain_core.utils.input import get_bolded_text, get_colored_text

[docs]class LoggingCallbackHandler(FunctionCallbackHandler): """Tracer that logs via the input Logger.""" name: str = "logging_callback_handler"
[docs] def __init__( self, logger: logging.Logger, log_level: int = logging.INFO, extra: Optional[dict] = None, **kwargs: Any, ) -> None: log_method = getattr(logger, logging.getLevelName(level=log_level).lower()) def callback(text: str) -> None: log_method(text, extra=extra) super().__init__(function=callback, **kwargs)
[docs] def on_text( self, text: str, *, run_id: UUID, parent_run_id: Optional[UUID] = None, **kwargs: Any, ) -> None: try: crumbs_str = f"[{self.get_breadcrumbs(run=self._get_run(run_id=run_id))}] " except TracerException: crumbs_str = "" self.function_callback( f'{get_colored_text("[text]", color="blue")}' f' {get_bolded_text(f"{crumbs_str}New text:")}\n{text}' )