langchain/templates/rag-multi-index-router/rag_multi_index_router/chain.py
2023-11-18 14:42:22 -08:00

114 lines
3.2 KiB
Python

from operator import itemgetter
from typing import Literal
from langchain.chat_models import ChatOpenAI
from langchain.output_parsers.openai_functions import PydanticAttrOutputFunctionsParser
from langchain.prompts import ChatPromptTemplate
from langchain.pydantic_v1 import BaseModel, Field
from langchain.retrievers import (
ArxivRetriever,
KayAiRetriever,
PubMedRetriever,
WikipediaRetriever,
)
from langchain.schema import StrOutputParser
from langchain.schema.runnable import (
RouterRunnable,
RunnableParallel,
RunnablePassthrough,
)
from langchain.utils.openai_functions import convert_pydantic_to_openai_function
pubmed = PubMedRetriever(top_k_results=5).with_config(run_name="pubmed")
arxiv = ArxivRetriever(top_k_results=5).with_config(run_name="arxiv")
sec = KayAiRetriever.create(
dataset_id="company", data_types=["10-K"], num_contexts=5
).with_config(run_name="sec_filings")
wiki = WikipediaRetriever(top_k_results=5, doc_content_chars_max=2000).with_config(
run_name="wiki"
)
llm = ChatOpenAI(model="gpt-3.5-turbo")
class Search(BaseModel):
"""Search for relevant documents by question topic."""
question_resource: Literal[
"medical paper", "scientific paper", "public company finances report", "general"
] = Field(
...,
description=(
"The type of resource that would best help answer the user's question. "
"If none of the types are relevant return 'general'."
),
)
retriever_name = {
"medical paper": "PubMed",
"scientific paper": "ArXiv",
"public company finances report": "SEC filings (Kay AI)",
"general": "Wikipedia",
}
classifier = (
llm.bind(
functions=[convert_pydantic_to_openai_function(Search)],
function_call={"name": "Search"},
)
| PydanticAttrOutputFunctionsParser(
pydantic_schema=Search, attr_name="question_resource"
)
| retriever_name.get
)
retriever_map = {
"PubMed": pubmed,
"ArXiv": arxiv,
"SEC filings (Kay AI)": sec,
"Wikipedia": wiki,
}
router_retriever = RouterRunnable(runnables=retriever_map)
def format_docs(docs):
return "\n\n".join(f"Source {i}:\n{doc.page_content}" for i, doc in enumerate(docs))
system = """Answer the user question. Use the following sources to help \
answer the question. If you don't know the answer say "I'm not sure, I couldn't \
find information on {{topic}}."
Sources:
{sources}"""
prompt = ChatPromptTemplate.from_messages([("system", system), ("human", "{question}")])
class Question(BaseModel):
__root__: str
retriever_chain = (
{"input": itemgetter("question"), "key": itemgetter("retriever_choice")}
| router_retriever
| format_docs
).with_config(run_name="retrieve")
answer_chain = (
{"sources": retriever_chain, "question": itemgetter("question")}
| prompt
| llm
| StrOutputParser()
)
chain = (
(
RunnableParallel(
question=RunnablePassthrough(), retriever_choice=classifier
).with_config(run_name="classify")
| RunnablePassthrough.assign(answer=answer_chain).with_config(run_name="answer")
)
.with_config(run_name="QA with router")
.with_types(input_type=Question)
)