add loading output

app.py

@@ -24,6 +24,7 @@ client = InferenceClient(model_id, token=os.environ.get("INFERENCE_API_HF_TOKEN"
 save_dataset_hf_token = os.environ.get("SAVE_DATASET_HF_TOKEN")
 session = requests.Session()
 empty_dataframe = pd.DataFrame({"1": [], "2": [], "3": []})
+loading_dataframe = pd.DataFrame({"Loading...": ["..."]})
 
 NAMESPACE = "dataset-rewriter"
 URL = "https://huggingface.co/spaces/dataset-rewriter/dataset-rewriter"
@@ -348,7 +349,7 @@ with gr.Blocks(css=css) as demo:
         print(f"(preview) ReWriting {dataset} with instruction '{prompt}'")
         yield {rewrite_full_dataset_button: gr.Button(interactive=False), full_dataset_generation_label: gr.Label(visible=False)}
         yield {
-            pretty_output_preview: gr.DataFrame(visible=True),
+            pretty_output_preview: gr.DataFrame(loading_dataframe, visible=True),
             pretty_full_dataset_generation_output: gr.DataFrame(visible=False),
         }
         for row in stream_rewrite_dataset_preview_row_by_row(dataset=dataset, rows=rows, prompt=prompt, format=format):
@@ -371,7 +372,7 @@ with gr.Blocks(css=css) as demo:
         yield {pretty_full_dataset_generation_output: empty_dataframe}
         yield {
             pretty_output_preview: gr.DataFrame(visible=False),
-            pretty_full_dataset_generation_output: gr.DataFrame(visible=True),
+            pretty_full_dataset_generation_output: gr.DataFrame(loading_dataframe, visible=True),
         }
 
         num_parallel_calls = max(1, min(total // NUM_ROWS_PER_CALL, NUM_PARALLEL_CALLS))