app.py

import os
import textwrap

from llama_index.query_engine.retriever_query_engine import RetrieverQueryEngine


from llama_index import VectorStoreIndex, SimpleDirectoryReader, Document


from llama_index.vector_stores import DeepLakeVectorStore
from langchain.chat_models import ChatOpenAI
import chainlit as cl


import os
os.environ["OPENAI_API_KEY"]=  os.environ.get("open_ai")



from llama_index import SimpleDirectoryReader, Document, StorageContext, OpenAIEmbedding, ServiceContext, PromptHelper, VectorStoreIndex
from llama_index.vector_stores import PineconeVectorStore, QdrantVectorStore, SimpleVectorStore, DeepLakeVectorStore
from transformers import BertTokenizerFast
import openai
from llama_index.llms import OpenAI
from llama_index import ServiceContext
from llama_index.embeddings import OpenAIEmbedding
from llama_index.node_parser import SimpleNodeParser
from llama_index.text_splitter import TokenTextSplitter

from llama_index import StorageContext, load_index_from_storage
from llama_index import load_index_from_storage, load_indices_from_storage, load_graph_from_storage



#dataset_path ="hub://cxcxxaaaaaz/text_embedding" # if we comment this out and don't pass the path then GPTDeepLakeIndex will create dataset in memory
from llama_index.storage.storage_context import StorageContext
from llama_index import VectorStoreIndex, SimpleDirectoryReader, Document
from llama_index.vector_stores import ChromaVectorStore

# Create an index over the documnts
#vector_store = DeepLakeVectorStore(dataset_path=dataset_path



import chromadb

db2 = chromadb.PersistentClient(path="./chroma_db")
chroma_collection = db2.get_or_create_collection("vector")



vector_store = ChromaVectorStore(chroma_collection=chroma_collection)
storage_context = StorageContext.from_defaults(vector_store=vector_store)





#vector_store = LanceDBVectorStore1(uri="./sample_data/")


#storage_context = StorageContext.from_defaults(vector_store=vector_store)              


llm = OpenAI(model='gpt-3.5-turbo', temperature=0.1)
embed_model = OpenAIEmbedding()

#node_parser = SimpleNodeParser(text_splitter=TokenTextSplitter(chunk_size=2924, chunk_overlap=20))

prompt_helper = PromptHelper(
  context_window=2000,
  num_output=256,
  chunk_overlap_ratio=0.1,
  chunk_size_limit=200
)

import tiktoken
from llama_index.callbacks import CallbackManager, TokenCountingHandler
from llama_index import load_index_from_storage, load_indices_from_storage, load_graph_from_storage

token_counter = TokenCountingHandler(tokenizer=tiktoken.encoding_for_model("gpt-3.5-turbo").encode)

callback_manager = CallbackManager([token_counter])


service_context = ServiceContext.from_defaults(
  llm=llm,
  embed_model=embed_model
)
from llama_index import set_global_service_context



index = VectorStoreIndex.from_documents([], vectorstore=vector_store, storage_context=storage_context, service_context=service_context)



@cl.on_chat_start
async def factory():

        
    
# Substitute your connection string here
   
    query_engine = index.as_query_engine(
        service_context=service_context,
        streaming=True,
    )

    
    cl.user_session.set("query_engine", query_engine)



@cl.on_message
async def main(message: cl.Message):
    query_engine = cl.user_session.get("query_engine")  # type: RetrieverQueryEngine
    response = await cl.make_async(query_engine.query)(message.content)

    response_message = cl.Message(content="")

    for token in response.response_gen:
        await response_message.stream_token(token=token)

    if response.response_txt:
        response_message.content = response.response_txt

    await response_message.send()