src/doc_qa.py

from typing import Optional, List

from langchain.document_loaders import TextLoader  #for textfiles
from langchain.text_splitter import CharacterTextSplitter #text splitter
from langchain.embeddings import HuggingFaceEmbeddings #for using HugginFace models

from langchain.document_loaders import UnstructuredPDFLoader  #load pdf
from langchain.indexes import VectorstoreIndexCreator #vectorize db index with chromadb
from langchain.chains import RetrievalQA
from langchain.document_loaders import UnstructuredURLLoader  #load urls into docoument-loader
from langchain.chains.question_answering import load_qa_chain
from langchain import HuggingFaceHub
import os
from langchain.document_loaders import TextLoader, PyMuPDFLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.llms import HuggingFacePipeline
from langchain.vectorstores import FAISS
from langchain.embeddings import HuggingFaceEmbeddings
from langchain import PromptTemplate
from langchain.chains import LLMChain
from langchain.base_language import BaseLanguageModel
from docx import Document
from langchain.document_loaders import DirectoryLoader
multi_directory_path=r'tmp/'

from transformers import pipeline

from sentence_transformers import SentenceTransformer
#model = SentenceTransformer("sentence-transformers/LaBSE")
embeddings = HuggingFaceEmbeddings(model_name='setu4993/LaBSE')

from langchain_community.document_loaders import TextLoader, PyPDFLoader, Docx2txtLoader

after_rag_template = """Answer the question based only on the following context:
   {context}
   Question: {question}
   """
#pipe = pipeline("text2text-generation", model="google/flan-t5-large" ,max_new_tokens=100)
#pipe = pipeline("text2text-generation", model="google/mt5-large" ,max_new_tokens=200)
from transformers import pipeline, AutoTokenizer, AutoModelForSeq2SeqLM
#tokenizer = AutoTokenizer.from_pretrained("rinna/bilingual-gpt-neox-4b", use_fast=False)
#model = AutoModelForSeq2SeqLM.from_pretrained("google/mt5-base")
# Load model directly
from transformers import AutoTokenizer, AutoModelForCausalLM

#tokenizer = AutoTokenizer.from_pretrained("rinna/bilingual-gpt-neox-4b")
#model = AutoModelForCausalLM.from_pretrained("rinna/bilingual-gpt-neox-4b")
#pipe = pipeline("text2text-generation", model="rinna/bilingual-gpt-neox-4b" ,max_new_tokens=200)
#pipe = pipeline("text2text-generation", model=model, tokenizer=tokenizer, max_new_tokens=200)

pipe = pipeline("question-answering", model="deepset/xlm-roberta-base-squad2")

llm = HuggingFacePipeline(pipeline=pipe)

def run_custom_qa(question, retrieved_docs):
    context = " ".join([doc.page_content for doc in retrieved_docs])
    output = pipe(question=question, context=context)
    return output["answer"]

def docs_vector_index():
    from langchain.document_loaders import DirectoryLoader
    # Define a directory path
    directory_path = r"C:\Users\savni\PycharmProjects\DocsSearchEngine\tmp"

    # Create the DirectoryLoader, specifying loaders for each file type
    loader = DirectoryLoader(
        directory_path,
        glob="**/*",  # This pattern loads all files; modify as needed

    )
    docs = loader.load()

    text_splitter = RecursiveCharacterTextSplitter(
        chunk_size=1024, chunk_overlap=100, separators=[" ", ",", "\n", "."]
    )
    print(docs)
    docs_chunks = text_splitter.split_documents(docs)

    print(f"docs_chunks length: {len(docs_chunks)}")
    print('********************docs_chunks',docs_chunks)
    if len(docs_chunks)>0:
        db = FAISS.from_documents(docs_chunks, embeddings)
        return db
    else:
        return ''


#chain = load_qa_chain(llm, chain_type="stuff")

from langchain.prompts import PromptTemplate

template = """You are an artificial intelligence assistant. The assistant gives helpful, detailed, and polite answers to the user's questions. Below is some information. 
{context}

Based on the above information only, answer the below question. 

{question} Be concise."""

prompt = PromptTemplate.from_template(template)
print(prompt.input_variables)


#query_llm = LLMChain(llm=llm, prompt=prompt)

# def doc_qa1(query, db):
#     similar_doc = db.similarity_search(query, k=2)
#     doc_c=[]
#     for c in similar_doc:
#         doc_c.append(c.page_content)
#     context=''.join(doc_c)
#     #response = query_llm.run({"context": context, "question": query})
#     response = query_llm.run(context=context, question=query)
#     print('response',response)
#     return response

def doc_qa(query, db):
    print("*************************custom qa doc_qa",query)
    retriever = db.as_retriever()
    relevant_docs = retriever.get_relevant_documents(query)
    response=run_custom_qa(query, relevant_docs)
    print('response', response)
    return response