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import os
import streamlit as st
from dotenv import load_dotenv
from langchain_community.embeddings import HuggingFaceEmbeddings
from langchain_community.llms import llamacpp
from langchain_core.runnables.history import RunnableWithMessageHistory
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.callbacks import CallbackManager, StreamingStdOutCallbackHandler
from langchain.chains import create_history_aware_retriever, create_retrieval_chain, ConversationalRetrievalChain
from langchain.document_loaders import TextLoader
from langchain.chains.combine_documents import create_stuff_documents_chain
from langchain_community.chat_message_histories.streamlit import StreamlitChatMessageHistory
from langchain.prompts import PromptTemplate
from langchain.vectorstores import Chroma
from utills import load_txt_documents, split_docs, load_uploaded_documents, retriever_from_chroma
from langchain.text_splitter import TokenTextSplitter, RecursiveCharacterTextSplitter
from langchain_community.document_loaders.directory import DirectoryLoader
from HTML_templates import css, bot_template, user_template
def retriever_from_chroma(docs, search_type, k):
model_name = "sentence-transformers/all-mpnet-base-v2"
model_kwargs = {'device': 'cpu'}
encode_kwargs = {'normalize_embeddings': True}
embeddings = HuggingFaceEmbeddings(
model_name=model_name,
model_kwargs=model_kwargs,
encode_kwargs=encode_kwargs
)
vectorstore_path = "docs/chroma/"
if not os.path.exists(vectorstore_path):
os.makedirs(vectorstore_path)
vectorstore = Chroma.from_documents(
documents=text_chunks, embedding=embeddings, persist_directory="docs/chroma/")
retriever = vectordb.as_retriever(search_type=search_type, search_kwargs={"k": k})
return retriever
data_path = "data"
documents = []
for filename in os.listdir(data_path):
if filename.endswith('.txt'):
file_path = os.path.join(data_path, filename)
documents = TextLoader(file_path).load()
documents.extend(documents)
docs = split_docs(documents, 250, 20)
retriever = retriever_from_chroma(docs,'mmr',7)
def main(retriever):
st.set_page_config(page_title="Chat with multiple PDFs",
page_icon=":books:")
st.write(css, unsafe_allow_html=True)
if "conversation" not in st.session_state:
st.session_state.conversation = None
if "chat_history" not in st.session_state:
st.session_state.chat_history = None
st.header("Chat with multiple PDFs :books:")
with st.chat_message("Assistant"):
st.write("Hello my name is Robert, how can i help you? ")
user_question = st.text_input("Ask a question about your documents:")
with st.chat_message("User"):
st.write(user_question)
if user_question:
handle_userinput(user_question,vectorstore)
def handle_userinput(user_question,retriever):
docs = retriever.invoke(question)
doc_txt = [doc.page_content for doc in docs]
Rag_chain = create_conversational_rag_chain(retriever)
response = rag_chain.invoke({"context": doc_txt, "question": question})
with st.chat_message("Assistant"):
st.write(response)
def create_conversational_rag_chain(retriever):
model_path = ('qwen2-0_5b-instruct-q4_0.gguf')
callback_manager = CallbackManager([StreamingStdOutCallbackHandler()])
llm = llamacpp.LlamaCpp(
model_path=model_path,
n_gpu_layers=1,
temperature=0.1,
top_p=0.9,
n_ctx=22000,
max_tokens=200,
repeat_penalty=1.7,
# callback_manager=callback_manager,
verbose=False,
)
template = """Answer the question based only on the following context:
{context}
Question: {question}
"""
prompt = ChatPromptTemplate.from_template(template)
rag_chain = prompt | llm | StrOutputParser()
return rag_chain
if __name__ == "__main__":
main(vectorstore)