app.py

import gradio as gr


data=["a","b","c","d"]
max_textboxes = len(data)
def click_event(slim, talk):
    talk=slim
    return talk

def variable_outputs(k):
    k = int(k)
    return [gr.Button(visible=True)]*k + [gr.Button(visible=False)]*(max_textboxes-k)

with gr.Blocks() as demo:
    
    arf = ''
    out_box = gr.Textbox()
    s = gr.Slider(1, max_textboxes, value=max_textboxes, step=1, label="How many textboxes to show:")
    textboxes = []
    for i in range(max_textboxes):
        t = gr.Button(value=f"{data[i]}")
        textboxes.append(t)
        arf = textboxes[i]
        arf.click(click_event, arf, out_box)

    s.change(variable_outputs, s, textboxes)

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