Update app.py

app.py

@@ -94,21 +94,31 @@ for doc in data:
 # -------------------------------
 
 # Create a Chroma vector store using the document splits.
-persist_directory = "./chroma_db"
-if os.path.exists(persist_directory):
-    print(f"Clearing existing vector store at {persist_directory}...")
-    shutil.rmtree(persist_directory)
+persist_directory = "path_to_persist_directory"
 
-# -------------------------------
-# Set Up Retrievers
-# -------------------------------
-# Create a Chroma vector store using the document splits.
-vectorstore = Chroma.from_documents(
-    documents=all_splits, 
-    embedding=OpenAIEmbeddings(), 
-    persist_directory=persist_directory
-)
-print("Created new vector store and persisted embeddings.")
+# Check if the directory exists and contains a persisted vector store
+if os.path.exists(persist_directory):
+    # Attempt to load the existing vector store
+    try:
+        vectorstore = Chroma.load(persist_directory, embedding_function=OpenAIEmbeddings())
+        print("Loaded existing vector store from persisted directory.")
+    except Exception as e:
+        print(f"Error loading vector store: {e}. Proceeding to create a new one.")
+        # Fallback to creating a new vector store if loading fails
+        vectorstore = Chroma.from_documents(
+            documents=all_splits, 
+            embedding=OpenAIEmbeddings(), 
+            persist_directory=persist_directory
+        )
+        print("Created new vector store and persisted embeddings.")
+else:
+    # Create a new vector store if the directory doesn't exist
+    vectorstore = Chroma.from_documents(
+        documents=all_splits, 
+        embedding=OpenAIEmbeddings(), 
+        persist_directory=persist_directory
+    )
+    print("Created new vector store and persisted embeddings.")
 
 # Create a BM25 retriever from the document splits.
 bm25_retriever = BM25Retriever.from_documents(all_splits)