app.py

#!/usr/bin/env python

import pathlib

import gradio as gr

paths = [path.as_posix() for path in sorted(pathlib.Path('images').glob('*'))]


def fn(data: gr.SelectData) -> int:
    return data.index


with gr.Blocks() as demo:
    images = gr.Gallery(value=paths).style(grid=3)
    selected = gr.Text(label='selected index')
    images.select(fn=fn, outputs=selected)
demo.queue(api_open=False).launch()