gradio/demo/hello_world_2/run.py

import gradio as gr

def greet(name):
    return "Hello " + name + "!"

iface = gr.Interface(
    fn=greet,
    inputs=gr.inputs.Textbox(lines=2, placeholder="Name Here..."),
    outputs="text",
)
if __name__ == "__main__":
    iface.launch()