gradio/demo/input_output/run.py

import gradio as gr

def image_mod(text):
    return text[::-1]

demo = gr.Blocks()

with demo:
    text = gr.Textbox(label="Input-Output")
    btn = gr.Button("Run")
    btn.click(image_mod, text, text)

if __name__ == "__main__":
    demo.launch()