pdf-chatbot / app.py
clementsan
Add PDF chatbot application
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import gradio as gr
import os
from langchain.document_loaders import PyPDFLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.vectorstores import Chroma
from langchain.chains import ConversationalRetrievalChain
from langchain.embeddings import HuggingFaceEmbeddings
from langchain.llms import HuggingFacePipeline
from langchain.chains import ConversationChain
from langchain.memory import ConversationBufferMemory
from langchain.llms import HuggingFaceHub
from transformers import AutoTokenizer
import transformers
import torch
import tqdm
import accelerate
default_persist_directory = './chroma_HF/'
default_llm_name1 = "tiiuae/falcon-7b-instruct"
default_llm_name2 = "google/flan-t5-xxl"
default_llm_name3 = "mosaicml/mpt-7b-instruct"
default_llm_name4 = "meta-llama/Llama-2-7b-chat-hf"
default_llm_name5 = "mistralai/Mistral-7B-Instruct-v0.1"
list_llm = [default_llm_name1, default_llm_name2, default_llm_name3, default_llm_name4, default_llm_name5]
# Load PDF document and create doc splits
def load_doc(list_file_path, chunk_size, chunk_overlap):
# Processing for one document only
# loader = PyPDFLoader(file_path)
# pages = loader.load()
loaders = [PyPDFLoader(x) for x in list_file_path]
pages = []
for loader in loaders:
pages.extend(loader.load())
# text_splitter = RecursiveCharacterTextSplitter(chunk_size = 600, chunk_overlap = 50)
text_splitter = RecursiveCharacterTextSplitter(
chunk_size = chunk_size,
chunk_overlap = chunk_overlap)
doc_splits = text_splitter.split_documents(pages)
return doc_splits
# Create vector database
def create_db(splits):
embedding = HuggingFaceEmbeddings()
vectordb = Chroma.from_documents(
documents=splits,
embedding=embedding,
persist_directory=default_persist_directory
)
return vectordb
# Load vector database
def load_db():
embedding = HuggingFaceEmbeddings()
vectordb = Chroma(
persist_directory=default_persist_directory,
embedding_function=embedding)
return vectordb
# Initialize langchain LLM chain
def initialize_llmchain(llm_model, temperature, max_tokens, top_k, vector_db, progress=gr.Progress()):
progress(0.1, desc="Initializing HF tokenizer...")
# HuggingFacePipeline uses local model
# Warning: it will download model locally...
# tokenizer=AutoTokenizer.from_pretrained(llm_model)
# progress(0.5, desc="Initializing HF pipeline...")
# pipeline=transformers.pipeline(
# "text-generation",
# model=llm_model,
# tokenizer=tokenizer,
# torch_dtype=torch.bfloat16,
# trust_remote_code=True,
# device_map="auto",
# # max_length=1024,
# max_new_tokens=max_tokens,
# do_sample=True,
# top_k=top_k,
# num_return_sequences=1,
# eos_token_id=tokenizer.eos_token_id
# )
# llm = HuggingFacePipeline(pipeline=pipeline, model_kwargs={'temperature': temperature})
# HuggingFaceHub uses HF inference endpoints
progress(0.5, desc="Initializing HF Hub...")
llm = HuggingFaceHub(
repo_id=llm_model,
model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k}
)
progress(0.5, desc="Defining buffer memory...")
memory = ConversationBufferMemory(
memory_key="chat_history",
return_messages=True
)
# retriever=vector_db.as_retriever(search_type="similarity", search_kwargs={'k': 3})
retriever=vector_db.as_retriever()
progress(0.8, desc="Defining retrieval chain...")
global qa_chain
qa_chain = ConversationalRetrievalChain.from_llm(
llm,
retriever=retriever,
chain_type="stuff",
memory=memory,
# combine_docs_chain_kwargs={"prompt": your_prompt})
# return_source_documents=True,
# return_generated_question=True,
# verbose=True,
)
progress(0.9, desc="Done!")
# return qa_chain
# Initialize all elements
def initialize_database(list_file_obj, chunk_size, chunk_overlap, progress=gr.Progress()):
# Create list of documents (when valid)
#file_path = file_obj.name
list_file_path = [x.name for x in list_file_obj if x is not None]
print('list_file_path', list_file_path)
progress(0.25, desc="Loading document...")
# Load document and create splits
doc_splits = load_doc(list_file_path, chunk_size, chunk_overlap)
# Create or load Vector database
progress(0.5, desc="Generating vector database...")
# global vector_db
vector_db = create_db(doc_splits)
progress(0.9, desc="Done!")
return vector_db, "Complete!"
#return qa_chain
def initialize_LLM(llm_option, llm_temperature, max_tokens, top_k, vector_db, progress=gr.Progress()):
print("llm_option",llm_option)
llm_name = list_llm[llm_option]
print("llm_name",llm_name)
initialize_llmchain(llm_name, llm_temperature, max_tokens, top_k, vector_db, progress)
return "Complete!"
#return qa_chain
def format_chat_history(message, chat_history):
formatted_chat_history = []
for user_message, bot_message in chat_history:
formatted_chat_history.append(f"User: {user_message}")
formatted_chat_history.append(f"Assistant: {bot_message}")
return formatted_chat_history
def conversation(message, history):
formatted_chat_history = format_chat_history(message, history)
#print("formatted_chat_history",formatted_chat_history)
# Generate response using QA chain
response = qa_chain({"question": message, "chat_history": formatted_chat_history})
# return response['answer']
# Append user message and response to chat history
new_history = history + [(message, response["answer"])]
return gr.update(value=""), new_history
def upload_file(file_obj):
list_file_path = []
for idx, file in enumerate(file_obj):
file_path = file_obj.name
list_file_path.append(file_path)
# print(file_path)
# initialize_database(file_path, progress)
return list_file_path
def demo():
with gr.Blocks(theme="base") as demo:
vector_db = gr.Variable()
# qa_chain = gr.Variable()
gr.Markdown(
"""<center><h2> Document-based chatbot</center></h2>
<h3>Ask any questions about your PDF documents (single or multiple)</h3>
<i>Note: chatbot performs question-answering using Langchain and LLMs</i>
""")
with gr.Tab("Step 1 - Document pre-processing"):
with gr.Row():
document = gr.Files(height=100, file_count="multiple", file_types=["pdf"], interactive=True, label="Upload PDF Documents")
# upload_btn = gr.UploadButton("Loading document...", height=100, file_count="multiple", file_types=["pdf"], scale=1)
with gr.Row():
db_btn = gr.Radio(["ChromaDB"], label="Vector database", value = "ChromaDB", type="index", info="Choose your vector database")
with gr.Accordion("Advanced options - Text splitter", open=False):
with gr.Row():
slider_chunk_size = gr.Slider(minimum = 100, maximum = 1000, value=600, step=20, label="Chunk size", info="Chunk size", interactive=True)
with gr.Row():
slider_chunk_overlap = gr.Slider(minimum = 10, maximum = 200, value=50, step=10, label="Chunk overlap", info="Chunk overlap", interactive=True)
with gr.Row():
db_progress = gr.Textbox(label="Database Initialization", value="None")
with gr.Row():
db_btn = gr.Button("Generating vector database...")
with gr.Tab("Step 2 - Initializing QA chain"):
with gr.Row():
llm_btn = gr.Radio(["falcon-7b-instruct", "flan-t5-xxl", "mpt-7b-instruct", "Llama-2-7b-chat-hf", "Mistral-7B-Instruct-v0.1"], \
label="LLM", value = "falcon-7b-instruct", type="index", info="Choose your LLM model")
with gr.Accordion("Advanced options - LLM", open=False):
slider_temperature = gr.Slider(minimum = 0.0, maximum = 1.0, value=0.7, step=0.1, label="Temperature", info="Model temperature", interactive=True)
slider_maxtokens = gr.Slider(minimum = 256, maximum = 4096, value=1024, step=24, label="Max Tokens", info="Model max tokens", interactive=True)
slider_topk = gr.Slider(minimum = 1, maximum = 10, value=3, step=1, label="top-k samples", info="Model top-k samples", interactive=True)
with gr.Row():
llm_progress = gr.Textbox(value="None",label="QA chain Initialization")
with gr.Row():
qachain_btn = gr.Button("QA chain Initialization...")
with gr.Tab("Step 3 - Conversation"):
chatbot = gr.Chatbot(height=600)
with gr.Row():
msg = gr.Textbox(placeholder="Type message", container=True)
with gr.Row():
submit_btn = gr.Button("Submit")
clear_btn = gr.ClearButton([msg, chatbot])
# Preprocessing events
#upload_btn.upload(upload_file, inputs=[upload_btn], outputs=[document])
db_btn.click(initialize_database, inputs=[document, slider_chunk_size, slider_chunk_overlap], outputs=[vector_db, db_progress])
qachain_btn.click(initialize_LLM, inputs=[llm_btn, slider_temperature, slider_maxtokens, slider_topk, vector_db], outputs=[llm_progress]).then(lambda: None, None, chatbot, queue=False)
# Chatbot events
msg.submit(conversation, [msg, chatbot], [msg, chatbot], queue=False)
submit_btn.click(conversation, inputs=[msg, chatbot], outputs=[msg, chatbot], queue=False)
clear_btn.click(lambda: None, None, chatbot, queue=False)
demo.queue(concurrency_count=20).launch(debug=True)
if __name__ == "__main__":
demo()