Files
crewAI/crewai/agents/output_parser.py
João Moura af9e749edb Adding tool caching a loop execution prevention. (#25)
* Adding tool caching a loop execution prevention.

This adds some guardrails, to both prevent the same tool to be used
consecutively and also caching tool's results across the entire crew
so it cuts down execution time and eventual LLM calls.

This plays a huge role for smaller opensource models that usually fall
into those behaviors patterns.

It also includes some smaller improvements around the tool prompt and
agent tools, all with the same intention of guiding models into
better conform with agent instructions.
2023-12-29 22:35:23 -03:00

82 lines
2.6 KiB
Python

import re
from typing import Union
from langchain.agents.output_parsers import ReActSingleInputOutputParser
from langchain_core.agents import AgentAction, AgentFinish
from langchain_core.exceptions import OutputParserException
from .cache_handler import CacheHandler
from .tools_handler import ToolsHandler
FINAL_ANSWER_ACTION = "Final Answer:"
FINAL_ANSWER_AND_PARSABLE_ACTION_ERROR_MESSAGE = (
"Parsing LLM output produced both a final answer and a parse-able action:"
)
class CrewAgentOutputParser(ReActSingleInputOutputParser):
"""Parses ReAct-style LLM calls that have a single tool input.
Expects output to be in one of two formats.
If the output signals that an action should be taken,
should be in the below format. This will result in an AgentAction
being returned.
```
Thought: agent thought here
Action: search
Action Input: what is the temperature in SF?
```
If the output signals that a final answer should be given,
should be in the below format. This will result in an AgentFinish
being returned.
```
Thought: agent thought here
Final Answer: The temperature is 100 degrees
```
It also prevents tools from being reused in a roll.
"""
class Config:
arbitrary_types_allowed = True
tools_handler: ToolsHandler
cache: CacheHandler
def parse(self, text: str) -> Union[AgentAction, AgentFinish]:
includes_answer = FINAL_ANSWER_ACTION in text
regex = (
r"Action\s*\d*\s*:[\s]*(.*?)[\s]*Action\s*\d*\s*Input\s*\d*\s*:[\s]*(.*)"
)
action_match = re.search(regex, text, re.DOTALL)
if action_match:
if includes_answer:
raise OutputParserException(
f"{FINAL_ANSWER_AND_PARSABLE_ACTION_ERROR_MESSAGE}: {text}"
)
action = action_match.group(1).strip()
action_input = action_match.group(2)
tool_input = action_input.strip(" ")
tool_input = tool_input.strip('"')
last_tool_usage = self.tools_handler.last_used_tool
if last_tool_usage:
usage = {
"tool": action,
"input": tool_input,
}
if usage == last_tool_usage:
raise OutputParserException(
f"""\nI just used the {action} tool with input {tool_input}. So I already knwo the result of that."""
)
result = self.cache.read(action, tool_input)
if result:
return AgentFinish({"output": result}, text)
return super().parse(text)