Source code for langchain.callbacks.streamlit.streamlit_callback_handler
"""Callback Handler that prints to streamlit."""
from __future__ import annotations
from enum import Enum
from typing import TYPE_CHECKING, Any, Dict, List, NamedTuple, Optional
from langchain.callbacks.base import BaseCallbackHandler
from langchain.callbacks.streamlit.mutable_expander import MutableExpander
from langchain.schema import AgentAction, AgentFinish, LLMResult
if TYPE_CHECKING:
    from streamlit.delta_generator import DeltaGenerator
def _convert_newlines(text: str) -> str:
    """Convert newline characters to markdown newline sequences
    (space, space, newline).
    """
    return text.replace("\n", "  \n")
CHECKMARK_EMOJI = "✅"
THINKING_EMOJI = ":thinking_face:"
HISTORY_EMOJI = ":books:"
EXCEPTION_EMOJI = "⚠️"
[docs]class LLMThoughtState(Enum):
    """Enumerator of the LLMThought state."""
    # The LLM is thinking about what to do next. We don't know which tool we'll run.
    THINKING = "THINKING"
    # The LLM has decided to run a tool. We don't have results from the tool yet.
    RUNNING_TOOL = "RUNNING_TOOL"
    # We have results from the tool.
    COMPLETE = "COMPLETE"
[docs]class ToolRecord(NamedTuple):
    """The tool record as a NamedTuple."""
    name: str
    input_str: str
[docs]class LLMThoughtLabeler:
    """
    Generates markdown labels for LLMThought containers. Pass a custom
    subclass of this to StreamlitCallbackHandler to override its default
    labeling logic.
    """