update

app.py

@@ -307,14 +307,16 @@ demo: Optional[gr.Interface] = None  # Assign your gradio demo to this variable
 return_type = List[Hit]
 
 ## YOUR_CODE_STARTS_HERE
+# Building BM25 index and save:
 bm25_index = BM25Index.build_from_documents(
-        documents=iter(sciq.corpus),
-        ndocs=len(sciq.corpus),
-        k1=0.9,
-        b=0.4
-    )
-bm25_index.save("output/bm25_index_b")  # Save index to directory
-bm25_retriever = BM25Retriever(index_dir="output/bm25_index_b")
+    documents=iter(sciq.corpus),
+    ndocs=12160,
+    show_progress_bar=True
+)
+bm25_index.save("output/bm25_index")
+
+# Loading index and use BM25 retriever to retrieve:
+bm25_retriever = BM25Retriever(index_dir="output/bm25_index")
 
 corpus_dict = {doc.collection_id: doc.text for doc in sciq.corpus}
 
@@ -339,4 +341,4 @@ demo = gr.Interface(
     title="BM25 Query Engine"
 )
 ## YOUR_CODE_ENDS_HERE
-demo.launch()
+demo.launch()