Verified answer

Ответ:

import tkinter as tk

from tkinter import messagebox

window = tk.Tk()

window.title("Пример приложения с кнопкой")

label = tk.Label(text="Hello world!")

label.pack()

def say_hello():

messagebox.showinfo("Ответ", "Hello Again!")

button = tk.Button(text="Привет", command=say_hello)

button.pack()

window.mainloop()