app.py

from langchain.document_loaders import DirectoryLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.chat_models import ChatOpenAI
from langchain.retrievers.multi_query import MultiQueryRetriever
import dotenv
from langchain.indexes import VectorstoreIndexCreator
from langchain.chains.question_answering import load_qa_chain
from langchain.llms import OpenAI
from langchain.prompts import PromptTemplate
from langchain.chat_models import ChatOpenAI
from langchain.schema import AIMessage, HumanMessage, SystemMessage
import gradio as gr

dotenv.load_dotenv()


system_message = """You are the helpful assistant helping users with agricoulture questions.
If you don't know the answer, just say that you don't know, don't try to make up an answer.
"""

prompt_template = """Use the following pieces of context to answer the question at the end. 

Context:
{context}

Question: {question}
Answer:
"""
PROMPT = PromptTemplate(
    template=prompt_template, input_variables=["context", "question"]
)

loader = DirectoryLoader("./documents", glob="**/*.txt", show_progress=True)
docs = loader.load()
text_splitter = RecursiveCharacterTextSplitter(chunk_size=500, chunk_overlap=0)
texts = text_splitter.split_documents(docs)

embeddings = OpenAIEmbeddings()
docsearch = Chroma.from_documents(texts, embeddings).as_retriever()
chat = ChatOpenAI(temperature=0.1)


with gr.Blocks() as demo:
    chatbot = gr.Chatbot()
    msg = gr.Textbox()
    clear = gr.ClearButton([msg, chatbot])

    def respond(message, chat_history):
        messages = [
            SystemMessage(content=system_message),
        ]

        result_docs = docsearch.get_relevant_documents(message)
        human_message = None
        human_message = HumanMessage(
            content=PROMPT.format(context=result_docs[:4], question=message)
        )
        messages.append(human_message)

        result = chat(messages)
        bot_message = result.content
        chat_history.append((message, bot_message))
        return "", chat_history

    msg.submit(respond, [msg, chatbot], [msg, chatbot])


if __name__ == "__main__":
    demo.launch()