如何将函数与知识库结合使用

!pip install scipy --quiet
!pip install tenacity --quiet
!pip install tiktoken==0.3.3 --quiet
!pip install termcolor --quiet
!pip install openai --quiet
!pip install arxiv --quiet
!pip install pandas --quiet
!pip install PyPDF2 --quiet
!pip install tqdm --quiet

import os
import arxiv
import ast
import concurrent
import json
import os
import pandas as pd
import tiktoken
from csv import writer
from IPython.display import display, Markdown, Latex
from openai import OpenAI
from PyPDF2 import PdfReader
from scipy import spatial
from tenacity import retry, wait_random_exponential, stop_after_attempt
from tqdm import tqdm
from termcolor import colored

GPT_MODEL = "gpt-4o-mini"
EMBEDDING_MODEL = "text-embedding-ada-002"
client = OpenAI()

# Set a directory to store downloaded papers
data_dir = os.path.join(os.curdir, "data", "papers")
paper_dir_filepath = "./data/papers/arxiv_library.csv"

# Generate a blank dataframe where we can store downloaded files
df = pd.DataFrame(list())
df.to_csv(paper_dir_filepath)

@retry(wait=wait_random_exponential(min=1, max=40), stop=stop_after_attempt(3))
def embedding_request(text):
    response = client.embeddings.create(input=text, model=EMBEDDING_MODEL)
    return response


@retry(wait=wait_random_exponential(min=1, max=40), stop=stop_after_attempt(3))
def get_articles(query, library=paper_dir_filepath, top_k=10):
    """This function gets the top_k articles based on a user's query, sorted by relevance.
    It also downloads the files and stores them in arxiv_library.csv to be retrieved by the read_article_and_summarize.
    """
    client = arxiv.Client()
    search = arxiv.Search(
        query = query,
        max_results = top_k
    )
    result_list = []
    for result in client.results(search):
        result_dict = {}
        result_dict.update({"title": result.title})
        result_dict.update({"summary": result.summary})

        # Taking the first url provided
        result_dict.update({"article_url": [x.href for x in result.links][0]})
        result_dict.update({"pdf_url": [x.href for x in result.links][1]})
        result_list.append(result_dict)

        # Store references in library file
        response = embedding_request(text=result.title)
        file_reference = [
            result.title,
            result.download_pdf(data_dir),
            response.data[0].embedding,
        ]

        # Write to file
        with open(library, "a") as f_object:
            writer_object = writer(f_object)
            writer_object.writerow(file_reference)
            f_object.close()
    return result_list

def strings_ranked_by_relatedness(
    query: str,
    df: pd.DataFrame,
    relatedness_fn=lambda x, y: 1 - spatial.distance.cosine(x, y),
    top_n: int = 100,
) -> list[str]:
    """Returns a list of strings and relatednesses, sorted from most related to least."""
    query_embedding_response = embedding_request(query)
    query_embedding = query_embedding_response.data[0].embedding
    strings_and_relatednesses = [
        (row["filepath"], relatedness_fn(query_embedding, row["embedding"]))
        for i, row in df.iterrows()
    ]
    strings_and_relatednesses.sort(key=lambda x: x[1], reverse=True)
    strings, relatednesses = zip(*strings_and_relatednesses)
    return strings[:top_n]

def read_pdf(filepath):
    """Takes a filepath to a PDF and returns a string of the PDF's contents"""
    # creating a pdf reader object
    reader = PdfReader(filepath)
    pdf_text = ""
    page_number = 0
    for page in reader.pages:
        page_number += 1
        pdf_text += page.extract_text() + f"\nPage Number: {page_number}"
    return pdf_text


# Split a text into smaller chunks of size n, preferably ending at the end of a sentence
def create_chunks(text, n, tokenizer):
    """Returns successive n-sized chunks from provided text."""
    tokens = tokenizer.encode(text)
    i = 0
    while i < len(tokens):
        # Find the nearest end of sentence within a range of 0.5 * n and 1.5 * n tokens
        j = min(i + int(1.5 * n), len(tokens))
        while j > i + int(0.5 * n):
            # Decode the tokens and check for full stop or newline
            chunk = tokenizer.decode(tokens[i:j])
            if chunk.endswith(".") or chunk.endswith("\n"):
                break
            j -= 1
        # If no end of sentence found, use n tokens as the chunk size
        if j == i + int(0.5 * n):
            j = min(i + n, len(tokens))
        yield tokens[i:j]
        i = j


def extract_chunk(content, template_prompt):
    """This function applies a prompt to some input content. In this case it returns a summarized chunk of text"""
    prompt = template_prompt + content
    response = client.chat.completions.create(
        model=GPT_MODEL, messages=[{"role": "user", "content": prompt}], temperature=0
    )
    return response.choices[0].message.content


def summarize_text(query):
    """This function does the following:
    - Reads in the arxiv_library.csv file in including the embeddings
    - Finds the closest file to the user's query
    - Scrapes the text out of the file and chunks it
    - Summarizes each chunk in parallel
    - Does one final summary and returns this to the user"""

    # A prompt to dictate how the recursive summarizations should approach the input paper
    summary_prompt = """Summarize this text from an academic paper. Extract any key points with reasoning.\n\nContent:"""

    # If the library is empty (no searches have been performed yet), we perform one and download the results
    library_df = pd.read_csv(paper_dir_filepath).reset_index()
    if len(library_df) == 0:
        print("No papers searched yet, downloading first.")
        get_articles(query)
        print("Papers downloaded, continuing")
        library_df = pd.read_csv(paper_dir_filepath).reset_index()
    else:
        print("Existing papers found... Articles:", len(library_df))
    library_df.columns = ["title", "filepath", "embedding"]
    library_df["embedding"] = library_df["embedding"].apply(ast.literal_eval)
    strings = strings_ranked_by_relatedness(query, library_df, top_n=1)
    print("Chunking text from paper")
    pdf_text = read_pdf(strings[0])

    # Initialise tokenizer
    tokenizer = tiktoken.get_encoding("cl100k_base")
    results = ""

    # Chunk up the document into 1500 token chunks
    chunks = create_chunks(pdf_text, 1500, tokenizer)
    text_chunks = [tokenizer.decode(chunk) for chunk in chunks]
    print("Summarizing each chunk of text")

    # Parallel process the summaries
    with concurrent.futures.ThreadPoolExecutor(
        max_workers=len(text_chunks)
    ) as executor:
        futures = [
            executor.submit(extract_chunk, chunk, summary_prompt)
            for chunk in text_chunks
        ]
        with tqdm(total=len(text_chunks)) as pbar:
            for _ in concurrent.futures.as_completed(futures):
                pbar.update(1)
        for future in futures:
            data = future.result()
            results += data

    # Final summary
    print("Summarizing into overall summary")
    response = client.chat.completions.create(
        model=GPT_MODEL,
        messages=[
            {
                "role": "user",
                "content": f"""Write a summary collated from this collection of key points extracted from an academic paper.
                        The summary should highlight the core argument, conclusions and evidence, and answer the user's query.
                        User query: {query}
                        The summary should be structured in bulleted lists following the headings Core Argument, Evidence, and Conclusions.
                        Key points:\n{results}\nSummary:\n""",
            }
        ],
        temperature=0,
    )
    return response

@retry(wait=wait_random_exponential(min=1, max=40), stop=stop_after_attempt(3))
def chat_completion_request(messages, functions=None, model=GPT_MODEL):
    try:
        response = client.chat.completions.create(
            model=model,
            messages=messages,
            functions=functions,
        )
        return response
    except Exception as e:
        print("Unable to generate ChatCompletion response")
        print(f"Exception: {e}")
        return e

class Conversation:
    def __init__(self):
        self.conversation_history = []

    def add_message(self, role, content):
        message = {"role": role, "content": content}
        self.conversation_history.append(message)

    def display_conversation(self, detailed=False):
        role_to_color = {
            "system": "red",
            "user": "green",
            "assistant": "blue",
            "function": "magenta",
        }
        for message in self.conversation_history:
            print(
                colored(
                    f"{message['role']}: {message['content']}\n\n",
                    role_to_color[message["role"]],
                )
            )

# Initiate our get_articles and read_article_and_summarize functions
arxiv_functions = [
    {
        "name": "get_articles",
        "description": """Use this function to get academic papers from arXiv to answer user questions.""",
        "parameters": {
            "type": "object",
            "properties": {
                "query": {
                    "type": "string",
                    "description": f"""
                            User query in JSON. Responses should be summarized and should include the article URL reference
                            """,
                }
            },
            "required": ["query"],
        },
    },
    {
        "name": "read_article_and_summarize",
        "description": """Use this function to read whole papers and provide a summary for users.
        You should NEVER call this function before get_articles has been called in the conversation.""",
        "parameters": {
            "type": "object",
            "properties": {
                "query": {
                    "type": "string",
                    "description": f"""
                            Description of the article in plain text based on the user's query
                            """,
                }
            },
            "required": ["query"],
        },
    }
]

def chat_completion_with_function_execution(messages, functions=[None]):
    """This function makes a ChatCompletion API call with the option of adding functions"""
    response = chat_completion_request(messages, functions)
    full_message = response.choices[0]
    if full_message.finish_reason == "function_call":
        print(f"Function generation requested, calling function")
        return call_arxiv_function(messages, full_message)
    else:
        print(f"Function not required, responding to user")
        return response


def call_arxiv_function(messages, full_message):
    """Function calling function which executes function calls when the model believes it is necessary.
    Currently extended by adding clauses to this if statement."""

    if full_message.message.function_call.name == "get_articles":
        try:
            parsed_output = json.loads(
                full_message.message.function_call.arguments
            )
            print("Getting search results")
            results = get_articles(parsed_output["query"])
        except Exception as e:
            print(parsed_output)
            print(f"Function execution failed")
            print(f"Error message: {e}")
        messages.append(
            {
                "role": "function",
                "name": full_message.message.function_call.name,
                "content": str(results),
            }
        )
        try:
            print("Got search results, summarizing content")
            response = chat_completion_request(messages)
            return response
        except Exception as e:
            print(type(e))
            raise Exception("Function chat request failed")

    elif (
        full_message.message.function_call.name == "read_article_and_summarize"
    ):
        parsed_output = json.loads(
            full_message.message.function_call.arguments
        )
        print("Finding and reading paper")
        summary = summarize_text(parsed_output["query"])
        return summary

    else:
        raise Exception("Function does not exist and cannot be called")

# Start with a system message
paper_system_message = """You are arXivGPT, a helpful assistant pulls academic papers to answer user questions.
You summarize the papers clearly so the customer can decide which to read to answer their question.
You always provide the article_url and title so the user can understand the name of the paper and click through to access it.
Begin!"""
paper_conversation = Conversation()
paper_conversation.add_message("system", paper_system_message)