langchain/langchain/callbacks/stdout.py
Harrison Chase b7708bbec6
rfc: callback changes (#1165)
conceptually, no reason a tool should know what an "agent action" is

unless any objections, can change in all callback handlers
2023-02-20 22:54:15 -08:00

102 lines
3.0 KiB
Python

"""Callback Handler that prints to std out."""
from typing import Any, Dict, List, Optional, Union
from langchain.callbacks.base import BaseCallbackHandler
from langchain.input import print_text
from langchain.schema import AgentAction, AgentFinish, LLMResult
class StdOutCallbackHandler(BaseCallbackHandler):
"""Callback Handler that prints to std out."""
def __init__(self, color: Optional[str] = None) -> None:
"""Initialize callback handler."""
self.color = color
def on_llm_start(
self, serialized: Dict[str, Any], prompts: List[str], **kwargs: Any
) -> None:
"""Print out the prompts."""
pass
def on_llm_end(self, response: LLMResult, **kwargs: Any) -> None:
"""Do nothing."""
pass
def on_llm_new_token(self, token: str, **kwargs: Any) -> None:
"""Do nothing."""
pass
def on_llm_error(
self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any
) -> None:
"""Do nothing."""
pass
def on_chain_start(
self, serialized: Dict[str, Any], inputs: Dict[str, Any], **kwargs: Any
) -> None:
"""Print out that we are entering a chain."""
class_name = serialized["name"]
print(f"\n\n\033[1m> Entering new {class_name} chain...\033[0m")
def on_chain_end(self, outputs: Dict[str, Any], **kwargs: Any) -> None:
"""Print out that we finished a chain."""
print("\n\033[1m> Finished chain.\033[0m")
def on_chain_error(
self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any
) -> None:
"""Do nothing."""
pass
def on_tool_start(
self,
serialized: Dict[str, Any],
input_str: str,
**kwargs: Any,
) -> None:
"""Do nothing."""
pass
def on_agent_action(
self, action: AgentAction, color: Optional[str] = None, **kwargs: Any
) -> Any:
"""Run on agent action."""
print_text(action.log, color=color if color else self.color)
def on_tool_end(
self,
output: str,
color: Optional[str] = None,
observation_prefix: Optional[str] = None,
llm_prefix: Optional[str] = None,
**kwargs: Any,
) -> None:
"""If not the final action, print out observation."""
print_text(f"\n{observation_prefix}")
print_text(output, color=color if color else self.color)
print_text(f"\n{llm_prefix}")
def on_tool_error(
self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any
) -> None:
"""Do nothing."""
pass
def on_text(
self,
text: str,
color: Optional[str] = None,
end: str = "",
**kwargs: Optional[str],
) -> None:
"""Run when agent ends."""
print_text(text, color=color if color else self.color, end=end)
def on_agent_finish(
self, finish: AgentFinish, color: Optional[str] = None, **kwargs: Any
) -> None:
"""Run on agent end."""
print_text(finish.log, color=color if self.color else color, end="\n")