langchain/templates/retrieval-agent/retrieval_agent/chain.py
Erick Friis ed789be8f4
docs, templates: update schema imports to core (#17885)
- chat models, messages
- documents
- agentaction/finish
- baseretriever,document
- stroutputparser
- more messages
- basemessage
- format_document
- baseoutputparser

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>
2024-02-22 15:58:44 -08:00

121 lines
4.0 KiB
Python

import os
from typing import List, Tuple
from langchain.agents import AgentExecutor
from langchain.agents.format_scratchpad import format_to_openai_function_messages
from langchain.agents.output_parsers import OpenAIFunctionsAgentOutputParser
from langchain.callbacks.manager import CallbackManagerForRetrieverRun
from langchain.tools.retriever import create_retriever_tool
from langchain_community.tools.convert_to_openai import format_tool_to_openai_function
from langchain_community.utilities.arxiv import ArxivAPIWrapper
from langchain_core.documents import Document
from langchain_core.messages import AIMessage, HumanMessage
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.pydantic_v1 import BaseModel, Field
from langchain_core.retrievers import BaseRetriever
from langchain_openai import AzureChatOpenAI
class ArxivRetriever(BaseRetriever, ArxivAPIWrapper):
"""`Arxiv` retriever.
It wraps load() to get_relevant_documents().
It uses all ArxivAPIWrapper arguments without any change.
"""
get_full_documents: bool = False
def _get_relevant_documents(
self, query: str, *, run_manager: CallbackManagerForRetrieverRun
) -> List[Document]:
try:
if self.is_arxiv_identifier(query):
results = self.arxiv_search(
id_list=query.split(),
max_results=self.top_k_results,
).results()
else:
results = self.arxiv_search( # type: ignore
query[: self.ARXIV_MAX_QUERY_LENGTH], max_results=self.top_k_results
).results()
except self.arxiv_exceptions as ex:
return [Document(page_content=f"Arxiv exception: {ex}")]
docs = [
Document(
page_content=result.summary,
metadata={
"Published": result.updated.date(),
"Title": result.title,
"Authors": ", ".join(a.name for a in result.authors),
},
)
for result in results
]
return docs
description = (
"A wrapper around Arxiv.org "
"Useful for when you need to answer questions about Physics, Mathematics, "
"Computer Science, Quantitative Biology, Quantitative Finance, Statistics, "
"Electrical Engineering, and Economics "
"from scientific articles on arxiv.org. "
"Input should be a search query."
)
# Create the tool
arxiv_tool = create_retriever_tool(ArxivRetriever(), "arxiv", description)
tools = [arxiv_tool]
llm = AzureChatOpenAI(
temperature=0,
azure_endpoint=os.getenv("AZURE_OPENAI_ENDPOINT"),
api_key=os.getenv("AZURE_OPENAI_API_KEY"),
api_version=os.getenv("AZURE_OPENAI_API_VERSION"),
)
assistant_system_message = """You are a helpful research assistant. \
Lookup relevant information as needed."""
prompt = ChatPromptTemplate.from_messages(
[
("system", assistant_system_message),
MessagesPlaceholder(variable_name="chat_history"),
("user", "{input}"),
MessagesPlaceholder(variable_name="agent_scratchpad"),
]
)
llm_with_tools = llm.bind(functions=[format_tool_to_openai_function(t) for t in tools])
def _format_chat_history(chat_history: List[Tuple[str, str]]):
buffer = []
for human, ai in chat_history:
buffer.append(HumanMessage(content=human))
buffer.append(AIMessage(content=ai))
return buffer
agent = (
{
"input": lambda x: x["input"],
"chat_history": lambda x: _format_chat_history(x["chat_history"]),
"agent_scratchpad": lambda x: format_to_openai_function_messages(
x["intermediate_steps"]
),
}
| prompt
| llm_with_tools
| OpenAIFunctionsAgentOutputParser()
)
class AgentInput(BaseModel):
input: str
chat_history: List[Tuple[str, str]] = Field(
..., extra={"widget": {"type": "chat", "input": "input", "output": "output"}}
)
agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=True).with_types(
input_type=AgentInput
)