Update rag.py

rag.py

@@ -79,7 +79,12 @@ class DataEngineeringRAG:
 
     def _build_vectorstore(self) -> None:
         from langchain_community.document_loaders import PyPDFLoader
-        from langchain.text_splitter import RecursiveCharacterTextSplitter
+        try:
+            # LangChain >= 0.2 — split into dedicated package
+            from langchain_text_splitters import RecursiveCharacterTextSplitter
+        except ImportError:
+            # LangChain < 0.2 fallback
+            from langchain.text_splitter import RecursiveCharacterTextSplitter
         from langchain_community.vectorstores import Chroma
         from langchain_community.embeddings import HuggingFaceEmbeddings
 
@@ -129,7 +134,10 @@ class DataEngineeringRAG:
         """Lightweight fallback when PDF is missing (useful for CI / testing)."""
         from langchain_community.vectorstores import Chroma
         from langchain_community.embeddings import HuggingFaceEmbeddings
-        from langchain.schema import Document
+        try:
+            from langchain_core.documents import Document
+        except ImportError:
+            from langchain.schema import Document
 
         demo_docs = [
             Document(
@@ -167,4 +175,4 @@ class DataEngineeringRAG:
         self.retriever = self.vectorstore.as_retriever(search_kwargs={"k": 3})
         self._doc_count = len(demo_docs)
         self._initialized = True
-        print("✅ Demo mode active — 3 built-in DE patterns loaded")
+        print("✅ Demo mode active — 3 built-in DE patterns loaded")