app.py

#!/usr/bin/env python

import gradio as gr
import pandas as pd

df_orig = pd.DataFrame([], columns=['a', 'b'])

with gr.Blocks() as demo:
    df = gr.Dataframe(value=df_orig, interactive=False)
    btn = gr.Button()
    text = gr.Textbox()
    btn.click(fn=lambda x: x.shape, inputs=df, outputs=text)
demo.queue().launch()