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import gradio as gr |
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import os |
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from langchain_community.document_loaders import PyPDFLoader |
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from langchain.text_splitter import RecursiveCharacterTextSplitter |
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from langchain_community.vectorstores import Chroma |
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from langchain.chains import ConversationalRetrievalChain |
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from langchain_community.embeddings import HuggingFaceEmbeddings |
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from langchain_community.llms import HuggingFacePipeline |
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from langchain.chains import ConversationChain |
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from langchain.memory import ConversationBufferMemory |
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from langchain_community.llms import HuggingFaceEndpoint |
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from pathlib import Path |
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import chromadb |
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from unidecode import unidecode |
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from transformers import AutoTokenizer |
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import transformers |
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import torch |
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import tqdm |
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import accelerate |
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import re |
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static_pdf_link = "https://huggingface.co/spaces/CCCDev/PDFChat/resolve/main/Data-privacy-policy.pdf" |
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list_llm = ["mistralai/Mistral-7B-Instruct-v0.2", "mistralai/Mixtral-8x7B-Instruct-v0.1", |
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"mistralai/Mistral-7B-Instruct-v0.1", "google/gemma-7b-it", "google/gemma-2b-it", |
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"HuggingFaceH4/zephyr-7b-beta", "HuggingFaceH4/zephyr-7b-gemma-v0.1", |
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"meta-llama/Llama-2-7b-chat-hf", "microsoft/phi-2", |
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"TinyLlama/TinyLlama-1.1B-Chat-v1.0", "mosaicml/mpt-7b-instruct", "tiiuae/falcon-7b-instruct", |
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"google/flan-t5-xxl"] |
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list_llm_simple = [os.path.basename(llm) for llm in list_llm] |
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def load_doc(file_path, chunk_size, chunk_overlap): |
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loader = PyPDFLoader(file_path) |
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pages = loader.load() |
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text_splitter = RecursiveCharacterTextSplitter( |
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chunk_size=chunk_size, |
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chunk_overlap=chunk_overlap) |
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doc_splits = text_splitter.split_documents(pages) |
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return doc_splits |
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def create_db(splits, collection_name): |
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embedding = HuggingFaceEmbeddings() |
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new_client = chromadb.EphemeralClient() |
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vectordb = Chroma.from_documents( |
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documents=splits, |
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embedding=embedding, |
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client=new_client, |
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collection_name=collection_name, |
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) |
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return vectordb |
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def initialize_llmchain(llm_model, temperature, max_tokens, top_k, vector_db, progress=gr.Progress()): |
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progress(0.1, desc="Initializing HF tokenizer...") |
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progress(0.5, desc="Initializing HF Hub...") |
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if llm_model == "mistralai/Mixtral-8x7B-Instruct-v0.1": |
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llm = HuggingFaceEndpoint( |
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repo_id=llm_model, |
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temperature=temperature, |
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max_new_tokens=max_tokens, |
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top_k=top_k, |
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load_in_8bit=True, |
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) |
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elif llm_model in ["HuggingFaceH4/zephyr-7b-gemma-v0.1", "mosaicml/mpt-7b-instruct"]: |
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raise gr.Error("LLM model is too large to be loaded automatically on free inference endpoint") |
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elif llm_model == "microsoft/phi-2": |
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llm = HuggingFaceEndpoint( |
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repo_id=llm_model, |
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temperature=temperature, |
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max_new_tokens=max_tokens, |
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top_k=top_k, |
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trust_remote_code=True, |
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torch_dtype="auto", |
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) |
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elif llm_model == "TinyLlama/TinyLlama-1.1B-Chat-v1.0": |
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llm = HuggingFaceEndpoint( |
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repo_id=llm_model, |
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temperature=temperature, |
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max_new_tokens=250, |
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top_k=top_k, |
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) |
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elif llm_model == "meta-llama/Llama-2-7b-chat-hf": |
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raise gr.Error("Llama-2-7b-chat-hf model requires a Pro subscription...") |
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else: |
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llm = HuggingFaceEndpoint( |
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repo_id=llm_model, |
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temperature=temperature, |
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max_new_tokens=max_tokens, |
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top_k=top_k, |
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) |
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progress(0.75, desc="Defining buffer memory...") |
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memory = ConversationBufferMemory( |
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memory_key="chat_history", |
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output_key='answer', |
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return_messages=True |
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) |
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retriever = vector_db.as_retriever() |
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progress(0.8, desc="Defining retrieval chain...") |
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qa_chain = ConversationalRetrievalChain.from_llm( |
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llm, |
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retriever=retriever, |
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chain_type="stuff", |
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memory=memory, |
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return_source_documents=True, |
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verbose=False, |
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) |
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progress(0.9, desc="Done!") |
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return qa_chain |
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def create_collection_name(filepath): |
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collection_name = Path(filepath).stem |
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collection_name = collection_name.replace(" ", "-") |
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collection_name = unidecode(collection_name) |
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collection_name = re.sub('[^A-Za-z0-9]+', '-', collection_name) |
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collection_name = collection_name[:50] |
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if len(collection_name) < 3: |
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collection_name = collection_name + 'xyz' |
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if not collection_name[0].isalnum(): |
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collection_name = 'A' + collection_name[1:] |
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if not collection_name[-1].isalnum(): |
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collection_name = collection_name[:-1] + 'Z' |
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print('Filepath: ', filepath) |
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print('Collection name: ', collection_name) |
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return collection_name |
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def initialize_database(chunk_size, chunk_overlap, progress=gr.Progress()): |
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file_path = static_pdf_link |
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progress(0.1, desc="Creating collection name...") |
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collection_name = create_collection_name(file_path) |
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progress(0.25, desc="Loading document...") |
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doc_splits = load_doc(file_path, chunk_size, chunk_overlap) |
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progress(0.5, desc="Generating vector database...") |
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vector_db = create_db(doc_splits, collection_name) |
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progress(0.9, desc="Done!") |
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return vector_db, collection_name, "Complete!" |
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def initialize_LLM(llm_option, llm_temperature, max_tokens, top_k, vector_db, progress=gr.Progress()): |
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llm_name = list_llm[llm_option] |
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print("llm_name: ", llm_name) |
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qa_chain = initialize_llmchain(llm_name, llm_temperature, max_tokens, top_k, vector_db, progress) |
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return qa_chain, "Complete!" |
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def format_chat_history(message, chat_history): |
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formatted_chat_history = [] |
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for user_message, bot_message in chat_history: |
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formatted_chat_history.append(f"User: {user_message}") |
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formatted_chat_history.append(f"Assistant: {bot_message}") |
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return formatted_chat_history |
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def conversation(qa_chain, message, history): |
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formatted_chat_history = format_chat_history(message, history) |
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response = qa_chain({"question": message, "chat_history": formatted_chat_history}) |
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response_answer = response["answer"] |
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if response_answer.find("Helpful Answer:") != -1: |
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response_answer = response_answer.split("Helpful Answer:")[-1] |
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response_sources = response["source_documents"] |
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response_source1 = response_sources[0].page_content.strip() |
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response_source2 = response_sources[1].page_content.strip() |
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response_source3 = response_sources[2].page_content.strip() |
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response_source1_page = response_sources[0].metadata["page"] + 1 |
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response_source2_page = response_sources[1].metadata["page"] + 1 |
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response_source3_page = response_sources[2].metadata["page"] + 1 |
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new_history = history + [(message, response_answer)] |
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return qa_chain, gr.update( |
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value=""), new_history, response_source1, response_source1_page, response_source2, response_source2_page, response_source3, response_source3_page |
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def demo(): |
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with gr.Blocks(theme="base") as demo: |
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vector_db = gr.State() |
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qa_chain = gr.State() |
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collection_name = gr.State() |
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gr.Markdown( |
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"""<center><h2>PDF-based chatbot</center></h2> |
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<h3>Ask any questions about your PDF documents</h3>""") |
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gr.Markdown( |
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"""<b>Note:</b> This AI assistant, using Langchain and open-source LLMs, performs retrieval-augmented generation (RAG) from your PDF documents. \ |
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The user interface explicitely shows multiple steps to help understand the RAG workflow. |
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This chatbot takes past questions into account when generating answers (via conversational memory), and includes document references for clarity purposes.<br> |
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<br><b>Warning:</b> This space uses the free CPU Basic hardware from Hugging Face. Some steps and LLM models used below (free inference endpoints) can take some time to generate a reply. |
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""") |
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with gr.Tab("Step 2 - Process document"): |
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with gr.Row(): |
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db_btn = gr.Radio(["ChromaDB"], label="Vector database type", value="ChromaDB", type="index", |
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info="Choose your vector database") |
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with gr.Accordion("Advanced options - Document text splitter", open=False): |
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with gr.Row(): |
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chunk_size = gr.Slider(64, 4096, value=512, step=32, label="Text chunk size", |
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info="Text length of each document chunk being embedded into the vector database. Default is 512.") |
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chunk_overlap = gr.Slider(0, 1024, value=24, step=8, label="Text chunk overlap", |
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info="Text overlap between each document chunk being embedded into the vector database. Default is 24.") |
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initialize_db = gr.Button("Process document") |
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with gr.Row(): |
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output_db = gr.Textbox(label="Database initialization steps", placeholder="", show_label=False) |
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with gr.Accordion("Vector database collection details", open=False): |
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collection = gr.Textbox(label="Collection name", placeholder="", show_label=False) |
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with gr.Tab("Step 3 - Initialize LLM"): |
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with gr.Row(): |
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llm_options = gr.Dropdown(list_llm_simple, label="Choose open-source LLM", |
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value="Mistral-7B-Instruct-v0.2", |
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info="Choose among the proposed open-source LLMs") |
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with gr.Accordion("Advanced LLM options", open=False): |
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with gr.Row(): |
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llm_temperature = gr.Slider(0.01, 1.0, value=0.1, step=0.01, label="LLM temperature", |
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info="LLM sampling temperature, in [0.01,1.0] range. Default is 0.1") |
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llm_max_tokens = gr.Slider(32, 1024, value=512, step=16, label="Max tokens", |
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info="Maximum number of new tokens to be generated, in [32,1024] range. Default is 512") |
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llm_top_k = gr.Slider(1, 40, value=20, step=1, label="Top K", |
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info="The number of highest probability vocabulary tokens to keep for top-k-filtering. Default is 20.") |
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initialize_llm = gr.Button("Initialize LLM") |
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with gr.Row(): |
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output_llm = gr.Textbox(label="LLM initialization steps", placeholder="", show_label=False) |
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with gr.Tab("Step 4 - Start chatting"): |
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chatbot = gr.Chatbot(label="PDF chatbot", height=500) |
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msg = gr.Textbox(label="Your question", placeholder="Type your question here...", show_label=False) |
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clear = gr.Button("Clear chat") |
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with gr.Accordion("Document sources (3)", open=False): |
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gr.Markdown("Source 1") |
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response_src1 = gr.Textbox(label="Source 1", placeholder="", show_label=False) |
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response_src1_page = gr.Number(label="Page number", value=0, precision=0, interactive=False) |
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gr.Markdown("Source 2") |
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response_src2 = gr.Textbox(label="Source 2", placeholder="", show_label=False) |
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response_src2_page = gr.Number(label="Page number", value=0, precision=0, interactive=False) |
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gr.Markdown("Source 3") |
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response_src3 = gr.Textbox(label="Source 3", placeholder="", show_label=False) |
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response_src3_page = gr.Number(label="Page number", value=0, precision=0, interactive=False) |
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initialize_db.click(initialize_database, |
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inputs=[chunk_size, chunk_overlap], |
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outputs=[vector_db, collection_name, output_db]) |
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initialize_llm.click(initialize_LLM, |
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inputs=[llm_options, llm_temperature, llm_max_tokens, llm_top_k, vector_db], |
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outputs=[qa_chain, output_llm]) |
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msg.submit(conversation, |
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inputs=[qa_chain, msg, chatbot], |
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outputs=[chatbot, msg, chatbot, response_src1, response_src1_page, response_src2, response_src2_page, |
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response_src3, response_src3_page]) |
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clear.click(lambda: None, None, chatbot, queue=False) |
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clear.click(lambda: None, None, msg, queue=False) |
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return demo.queue().launch(debug=True) |
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if __name__ == "__main__": |
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demo() |
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