使用Llama index构建多代理 RAG

from llama_index import (
    VectorStoreIndex,
    SummaryIndex,
    SimpleKeywordTableIndex,
    SimpleDirectoryReader,
    ServiceContext,
 )
 from llama_index.schema import IndexNode
 from llama_index.tools import QueryEngineTool, ToolMetadata
 from llama_index.llms import OpenAI

wiki_titles = [
    "Toronto",
    "Seattle",
    "Chicago",
    "Boston",
    "Houston",
    "Tokyo",
    "Berlin",
    "Lisbon",
    "Paris",
    "London",
    "Atlanta",
    "Munich",
    "Shanghai",
    "Beijing",
    "Copenhagen",
    "Moscow",
    "Cairo",
    "Karachi",
 ]

from pathlib import Path
 
 import requests
 
 for title in wiki_titles:
    response = requests.get(
        "https://en.wikipedia.org/w/api.php",
        params={
            "action": "query",
            "format": "json",
            "titles": title,
            "prop": "extracts",
            # 'exintro': True,
            "explaintext": True,
        },
    ).json()
    page = next(iter(response["query"]["pages"].values()))
    wiki_text = page["extract"]
 
    data_path = Path("data")
    if not data_path.exists():
        Path.mkdir(data_path)
 
    with open(data_path / f"{title}.txt", "w") as fp:
        fp.write(wiki_text)

# Load all wiki documents
 city_docs = {}
 for wiki_title in wiki_titles:
    city_docs[wiki_title] = SimpleDirectoryReader(
        input_files=[f"data/{wiki_title}.txt"]
    ).load_data()

llm = OpenAI(temperature=0, model="gpt-3.5-turbo")
 service_context = ServiceContext.from_defaults(llm=llm)

from llama_index.agent import OpenAIAgent
 from llama_index import load_index_from_storage, StorageContext
 from llama_index.node_parser import SimpleNodeParser
 import os
 
 node_parser = SimpleNodeParser.from_defaults()
 
 # Build agents dictionary
 agents = {}
 query_engines = {}
 
 # this is for the baseline
 all_nodes = []
 
 for idx, wiki_title in enumerate(wiki_titles):
    nodes = node_parser.get_nodes_from_documents(city_docs[wiki_title])
    all_nodes.extend(nodes)
 
    if not os.path.exists(f"./data/{wiki_title}"):
        # build vector index
        vector_index = VectorStoreIndex(nodes, service_cnotallow=service_context)
        vector_index.storage_context.persist(
            persist_dir=f"./data/{wiki_title}"
        )
    else:
        vector_index = load_index_from_storage(
            StorageContext.from_defaults(persist_dir=f"./data/{wiki_title}"),
            service_cnotallow=service_context,
        )
 
    # build summary index
    summary_index = SummaryIndex(nodes, service_cnotallow=service_context)
    # define query engines
    vector_query_engine = vector_index.as_query_engine()
    summary_query_engine = summary_index.as_query_engine()
 
    # define tools
    query_engine_tools = [
        QueryEngineTool(
            query_engine=vector_query_engine,
            metadata=ToolMetadata(
                name="vector_tool",
                descriptinotallow=(
                    "Useful for questions related to specific aspects of"
                    f" {wiki_title} (e.g. the history, arts and culture,"
                    " sports, demographics, or more)."
                ),
            ),
        ),
        QueryEngineTool(
            query_engine=summary_query_engine,
            metadata=ToolMetadata(
                name="summary_tool",
                descriptinotallow=(
                    "Useful for any requests that require a holistic summary"
                    f" of EVERYTHING about {wiki_title}. For questions about"
                    " more specific sections, please use the vector_tool."
                ),
            ),
        ),
    ]
 
    # build agent
    function_llm = OpenAI(model="gpt-4")
    agent = OpenAIAgent.from_tools(
        query_engine_tools,
        llm=function_llm,
        verbose=True,
        system_prompt=f"""\
 You are a specialized agent designed to answer queries about {wiki_title}.
 You must ALWAYS use at least one of the tools provided when answering a question; do NOT rely on prior knowledge.\
 """,
    )
 
    agents[wiki_title] = agent
    query_engines[wiki_title] = vector_index.as_query_engine(
        similarity_top_k=2
    )

# define tool for each document agent
 all_tools = []
 for wiki_title in wiki_titles:
    wiki_summary = (
        f"This content contains Wikipedia articles about {wiki_title}. Use"
        f" this tool if you want to answer any questions about {wiki_title}.\n"
    )
    doc_tool = QueryEngineTool(
        query_engine=agents[wiki_title],
        metadata=ToolMetadata(
            name=f"tool_{wiki_title}",
            descriptinotallow=wiki_summary,
        ),
    )
    all_tools.append(doc_tool)
     
 # define an "object" index and retriever over these tools
 from llama_index import VectorStoreIndex
 from llama_index.objects import ObjectIndex, SimpleToolNodeMapping
 
 tool_mapping = SimpleToolNodeMapping.from_objects(all_tools)
 obj_index = ObjectIndex.from_objects(
    all_tools,
    tool_mapping,
    VectorStoreIndex,
 )
 
 from llama_index.agent import FnRetrieverOpenAIAgent
 
 top_agent = FnRetrieverOpenAIAgent.from_retriever(
    obj_index.as_retriever(similarity_top_k=3),
    system_prompt=""" \
 You are an agent designed to answer queries about a set of given cities.
 Please always use the tools provided to answer a question. Do not rely on prior knowledge.\
 
 """,
    verbose=True,
 )

base_index = VectorStoreIndex(all_nodes)
 base_query_engine = base_index.as_query_engine(similarity_top_k=4)

response = top_agent.query("Tell me about the arts and culture in Boston")

=== Calling Function ===
 Calling function: tool_Boston with args: {
  "input": "arts and culture"
 }
 === Calling Function ===
 Calling function: vector_tool with args: {
  "input": "arts and culture"
 }
 Got output: Boston is known for its vibrant arts and culture scene. The city is home to a number of performing arts organizations, including the Boston Ballet, Boston Lyric Opera Company, Opera Boston, Boston Baroque, and the Handel and Haydn Society. There are also several theaters in or near the Theater District, such as the Cutler Majestic Theatre, Citi Performing Arts Center, the Colonial Theater, and the Orpheum Theatre. Boston is a center for contemporary classical music, with groups like the Boston Modern Orchestra Project and Boston Musica Viva. The city also hosts major annual events, such as First Night, the Boston Early Music Festival, and the Boston Arts Festival. In addition, Boston has several art museums and galleries, including the Museum of Fine Arts, the Isabella Stewart Gardner Museum, and the Institute of Contemporary Art.
 ========================
 Got output: Boston is renowned for its vibrant arts and culture scene. It is home to numerous performing arts organizations, including the Boston Ballet, Boston Lyric Opera Company, Opera Boston, Boston Baroque, and the Handel and Haydn Society. The city's Theater District houses several theaters, such as the Cutler Majestic Theatre, Citi Performing Arts Center, the Colonial Theater, and the Orpheum Theatre.
 
 Boston is also a hub for contemporary classical music, with groups like the Boston Modern Orchestra Project and Boston Musica Viva. The city hosts major annual events, such as First Night, the Boston Early Music Festival, and the Boston Arts Festival, which contribute to its cultural richness.
 
 In terms of visual arts, Boston boasts several art museums and galleries. The Museum of Fine Arts, the Isabella Stewart Gardner Museum, and the Institute of Contemporary Art are among the most notable. These institutions offer a wide range of art collections, from ancient to contemporary, attracting art enthusiasts from around the world.
 ========================

# baseline
 response = base_query_engine.query(
    "Tell me about the arts and culture in Boston"
 )
 print(str(response))
 
 Boston has a rich arts and culture scene. The city is home to a variety of performing arts organizations, such as the Boston Ballet, Boston Lyric Opera Company, Opera Boston, Boston Baroque, and the Handel and Haydn Society. Additionally, there are numerous contemporary classical music groups associated with the city's conservatories and universities, like the Boston Modern Orchestra Project and Boston Musica Viva. The Theater District in Boston is a hub for theater, with notable venues including the Cutler Majestic Theatre, Citi Performing Arts Center, the Colonial Theater, and the Orpheum Theatre. Boston also hosts several significant annual events, including First Night, the Boston Early Music Festival, the Boston Arts Festival, and the Boston gay pride parade and festival. The city is renowned for its historic sites connected to the American Revolution, as well as its art museums and galleries, such as the Museum of Fine Arts, Isabella Stewart Gardner Museum, and the Institute of Contemporary Art.