app.py

# -*- coding: utf-8 -*-
"""wiki_chat_3_hack.ipynb

Automatically generated by Colaboratory.

Original file is located at
    https://colab.research.google.com/drive/1chXsWeq1LzbvYIs6H73gibYmNDRbIgkD
"""

#!pip install gradio

#!pip install -U sentence-transformers

#!pip install datasets

#!pip install langchain

#!pip install openai

#!pip install faiss-cpu

#import numpy as np
import gradio as gr
#import random
from sentence_transformers import SentenceTransformer, CrossEncoder, util
from torch import tensor as torch_tensor
from datasets import load_dataset

"""# import models"""

bi_encoder = SentenceTransformer('multi-qa-MiniLM-L6-cos-v1')
bi_encoder.max_seq_length = 256     #Truncate long passages to 256 tokens

#The bi-encoder will retrieve top_k documents. We use a cross-encoder, to re-rank the results list to improve the quality
cross_encoder = CrossEncoder('cross-encoder/ms-marco-MiniLM-L-6-v2')

"""# import datasets"""

dataset = load_dataset("gfhayworth/hack_policy", split='train')
mypassages = list(dataset.to_pandas()['psg'])

dataset_embed = load_dataset("gfhayworth/hack_policy_embed", split='train')
dataset_embed_pd = dataset_embed.to_pandas()
mycorpus_embeddings = torch_tensor(dataset_embed_pd.values)

def search(query, passages = mypassages, doc_embedding = mycorpus_embeddings, top_k=20, top_n = 1):
  question_embedding = bi_encoder.encode(query, convert_to_tensor=True)
  question_embedding = question_embedding #.cuda()
  hits = util.semantic_search(question_embedding, doc_embedding, top_k=top_k)
  hits = hits[0]  # Get the hits for the first query

  ##### Re-Ranking #####
  cross_inp = [[query, passages[hit['corpus_id']]] for hit in hits]
  cross_scores = cross_encoder.predict(cross_inp)

  # Sort results by the cross-encoder scores
  for idx in range(len(cross_scores)):
    hits[idx]['cross-score'] = cross_scores[idx]

  hits = sorted(hits, key=lambda x: x['cross-score'], reverse=True)
  predictions = hits[:top_n]
  return predictions
  # for hit in hits[0:3]:
  #     print("\t{:.3f}\t{}".format(hit['cross-score'], mypassages[hit['corpus_id']].replace("\n", " ")))

def get_text(qry):
  predictions = search(qry)
  prediction_text = []
  for hit in predictions:
    prediction_text.append("{}".format(mypassages[hit['corpus_id']]))
  return prediction_text

# def prt_rslt(qry):
  # rslt = get_text(qry)
  # for r in rslt:
  #   print(r)

# prt_rslt("What is the name of the plan described by this summary of benefits?")

"""# new LLM based functions"""

import os

from langchain.llms import OpenAI
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.embeddings import HuggingFaceEmbeddings

from langchain.text_splitter import CharacterTextSplitter
#from langchain.vectorstores.faiss import FAISS
from langchain.docstore.document import Document
from langchain.prompts import PromptTemplate
from langchain.chains.question_answering import load_qa_chain
from langchain.chains.qa_with_sources import load_qa_with_sources_chain
from langchain.chains import VectorDBQAWithSourcesChain

chain_qa = load_qa_with_sources_chain(OpenAI(temperature=0), chain_type="stuff")

def get_text_fmt(qry, passages = mypassages, doc_embedding=mycorpus_embeddings):
  predictions = search(qry, passages = passages, doc_embedding = doc_embedding, top_n=5, )
  prediction_text = []
  for hit in predictions:
    page_content = passages[hit['corpus_id']]
    metadata = {"source": hit['corpus_id']}
    result = Document(page_content=page_content, metadata=metadata)
    prediction_text.append(result)
  return prediction_text

#mypassages[0]

#mycorpus_embeddings[0][:5]

# query = "What is the name of the plan described by this summary of benefits?"
# mydocs = get_text_fmt(query)
# print(len(mydocs))
# for d in mydocs:
#   print(d)

# chain_qa.run(input_documents=mydocs, question=query)

def get_llm_response(message):
  mydocs = get_text_fmt(message)
  responses = chain_qa.run(input_documents=mydocs, question=message)
  return responses

"""# chat example"""

def chat(message, history):
  history = history or []
  message = message.lower()
  
  response = get_llm_response(message)
  history.append((message, response))
  return history, history

css=".gradio-container {background-color: lightgray}"

with gr.Blocks(css=css) as demo:
  history_state = gr.State()
  gr.Markdown('# Hack QA')
  title='Benefit Chatbot'
  description='chatbot with search on Health Benefits'
  with gr.Row():
    chatbot = gr.Chatbot()
  with gr.Row():
    message = gr.Textbox(label='Input your question here:',
                         placeholder='What is the name of the plan described by this summary of benefits?',
                         lines=1)
    submit = gr.Button(value='Send',
                       variant='secondary').style(full_width=False)
  submit.click(chat,
               inputs=[message, history_state],
               outputs=[chatbot, history_state])
  gr.Examples(
            examples=["What is the name of the plan described by this summary of benefits?",
                      "How much is the monthly premium?",
                      "How much do I have to pay if I am admitted to the hospital?"],
            inputs=message
        )

demo.launch()