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task-6a1864f7-ekzamen-rag-a…/agent.py
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Python

import os
from dotenv import load_dotenv
from langchain_ollama import OllamaLLM, OllamaEmbeddings
from langchain_chroma import Chroma
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_community.document_loaders import DirectoryLoader, TextLoader, UnstructuredMarkdownLoader
from langchain.tools import Tool
from langchain_community.tools.tavily_search import TavilySearchResults
from langchain.agents import initialize_agent, AgentType
# Load environment variables
load_dotenv()
TAVILY_API_KEY = os.getenv("TAVILY_API_KEY")
if not TAVILY_API_KEY:
raise ValueError("TAVILY_API_KEY not found in .env file")
# Configuration
PERSIST_DIRECTORY = "./chroma_db"
DOCUMENTS_DIR = "./documents"
EMBEDDING_MODEL = "nomic-embed-text"
LLM_MODEL = "llama3"
def setup_vectorstore():
"""Initialize or load ChromaDB vectorstore with Ollama embeddings."""
embeddings = OllamaEmbeddings(model=EMBEDDING_MODEL)
if os.path.exists(PERSIST_DIRECTORY) and os.listdir(PERSIST_DIRECTORY):
vectorstore = Chroma(
persist_directory=PERSIST_DIRECTORY,
embedding_function=embeddings
)
else:
# Load and process documents
loader = DirectoryLoader(
DOCUMENTS_DIR,
glob="**/*",
loader_cls=lambda path: TextLoader(path, encoding="utf-8") if path.endswith(".txt")
else UnstructuredMarkdownLoader(path) if path.endswith(".md")
else None,
show_progress=True,
use_multithreading=True
)
documents = loader.load()
text_splitter = RecursiveCharacterTextSplitter(
chunk_size=1000,
chunk_overlap=200,
length_function=len
)
texts = text_splitter.split_documents(documents)
vectorstore = Chroma.from_documents(
documents=texts,
embedding=embeddings,
persist_directory=PERSIST_DIRECTORY
)
vectorstore.persist()
return vectorstore
# Initialize vectorstore
vectorstore = setup_vectorstore()
# Define tools
def search_local_kb(query: str) -> str:
"""Search local knowledge base using ChromaDB."""
retriever = vectorstore.as_retriever(search_kwargs={"k": 3})
docs = retriever.get_relevant_documents(query)
return "\n\n".join([doc.page_content for doc in docs])
def web_search(query: str) -> str:
"""Search the web using Tavily."""
search = TavilySearchResults(tavily_api_key=TAVILY_API_KEY, max_results=3)
results = search.run(query)
return "\n\n".join([result["content"] for result in results])
# Create LangChain tools
local_tool = Tool(
name="search_local_kb",
func=search_local_kb,
description="Useful for answering questions about local documents stored in the knowledge base."
)
web_tool = Tool(
name="web_search",
func=web_search,
description="Useful for answering questions about current events, news, or general knowledge from the internet."
)
tools = [local_tool, web_tool]
# Initialize LLM
llm = OllamaLLM(model=LLM_MODEL)
# Create agent with routing logic
agent = initialize_agent(
tools=tools,
llm=llm,
agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION,
verbose=True,
handle_parsing_errors=True,
system_message="""You are an AI agent that must choose between two tools:
1. search_local_kb: For questions about local documents (concepts, notes, stored information)
2. web_search: For questions requiring up-to-date information from the internet
When answering, ALWAYS specify your information source:
- If using local knowledge base: [Source: chromadb]
- If using web search: [Source: tavily]
Be concise and accurate in your responses."""
)
# Chat interface
def main():
print("RAG Agent with ChromaDB and Tavily Web Search")
print("Type 'exit' to quit\n")
while True:
query = input("Запрос: ").strip()
if query.lower() == "exit":
break
if not query:
continue
try:
response = agent.run(query)
print(f"\n{response}\n")
except Exception as e:
print(f"Error: {str(e)}\n")
if __name__ == "__main__":
main()