Minor fix

app.py

@@ -36,7 +36,8 @@ def inference(pdf_path, chunk_size, chunk_overlap):
 
     index = pc.Index(host="https://langchain-test-index-la2n80y.svc.aped-4627-b74a.pinecone.io")
 
-    index.delete(delete_all=True)
+    if index.list():
+        index.delete(delete_all=True)
 
     chroma_db = Chroma.from_documents(documents, embeddings, persist_directory="./chroma_db")
     faiss_db = FAISS.from_documents(documents, embeddings)