streamlit_app.py

import os
import pathlib
import re
import streamlit as st
from streamlit_chat import message
from langchain.docstore.document import Document
from langchain.document_loaders import TextLoader
from langchain.text_splitter import CharacterTextSplitter
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.vectorstores import FAISS

st.set_page_config(
    page_title="LLM Chatbot"
)
st.header(" LLM Chatbot on Custom data")
st.sidebar.header("Instructions")
st.sidebar.info(
    '''This is a web application that allows you to interact with 
    your custom data
    '''
)
st.sidebar.info('''Enter a query in the text box and press enter
    to receive a response''')

st.sidebar.info('''
This project works perfectly even on your own data
''')

os.environ["OPENAI_API_KEY"] = "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"

from langchain.prompts.chat import (
    ChatPromptTemplate,
    SystemMessagePromptTemplate,
    HumanMessagePromptTemplate,
)
from langchain.chat_models import ChatOpenAI
from langchain.chains import RetrievalQAWithSourcesChain

# Initialize Streamlit
st.title("Stanlito AI Chatbot")

# Set the data store directory
DATA_STORE_DIR = "data_store"

# Upload the files `$DATA_STORE_DIR/index.faiss` and `$DATA_STORE_DIR/index.pkl` to local
if os.path.exists(DATA_STORE_DIR):
    vector_store = FAISS.load_local(
        DATA_STORE_DIR,
        OpenAIEmbeddings()
    )
else:
    st.write(f"Missing files. Upload index.faiss and index.pkl files to {DATA_STORE_DIR} directory first")

# Define system template
system_template = """Use the following pieces of context to answer the user's question.
Take note of the sources and include them in the answer in the format: "SOURCES: source1", use "SOURCES" in capital letters regardless of the number of sources.
If you don't know the answer, just say "I don't know", don't try to make up an answer.
----------------
{summaries}"""

# Create the prompt
messages = [
    SystemMessagePromptTemplate.from_template(system_template),
    HumanMessagePromptTemplate.from_template("{question}")
]
prompt = ChatPromptTemplate.from_messages(messages)

# Load the language model
llm = ChatOpenAI(model_name="gpt-3.5-turbo", temperature=0,
                 max_tokens=256)  # Modify model_name if you have access to GPT-4

# Create the chain
chain_type_kwargs = {"prompt": prompt}
chain = RetrievalQAWithSourcesChain.from_chain_type(
    llm=llm,
    chain_type="stuff",
    retriever=vector_store.as_retriever(),
    return_source_documents=True,
    chain_type_kwargs=chain_type_kwargs
)


# Define function to print the result
def print_result(result):
    output_text = f"""### Question:
    {query}
    Answer:
    {result['answer']}
    """
    st.markdown(output_text)


# Get user input
query = st.text_input("Ask a question")

# Process user input
if query:
    result = chain(query)
    print_result(result)