Update app.py

added: import uuid

app.py

@@ -5,6 +5,7 @@
 # from langchain_ibm import WatsonxLLM, WatsonxEmbeddings
 # from langchain.text_splitter import RecursiveCharacterTextSplitter
 # from langchain_text_splitters import RecursiveCharacterTextSplitter
+import uuid
 from langchain_text_splitters import RecursiveCharacterTextSplitter
 from langchain_community.vectorstores import Chroma
 from langchain_community.document_loaders import PyPDFLoader