app.py

import time
import gradio as gr
import spaces


@spaces.GPU
def stream(n: int):
    for i in range(n):
        msg = f"Step {i + 1}/{n}"
        print(msg)
        yield msg
        time.sleep(1)


with gr.Blocks() as demo:
    out = gr.Textbox()
    start = gr.Button("Start")
    stop = gr.Button("Stop", variant="stop")
    event = start.click(stream, gr.Slider(value=30), out)
    stop.click(fn=None, cancels=event)

demo.launch()