text: import tkinter as tk
  from tkinter import ttk
  
  ventana = tk.Tk()
  ventana.geometry("600x400")
  ventana.title("Ejemplo 3")
  
  ventana.rowconfigure(0, weight=1)
  ventana.rowconfigure(1, weight=5)
  
  ventana.columnconfigure(0, weight=1)
  ventana.columnconfigure(1, weight=5)
  
  # definicion de eventos
  
  def evento_uno():
      print("Evento 1")
  
  def evento_dos():
      print("Evento 2")    
  
  def evento_tres():
      print("Evento 3")
      
  def evento_cuatro():
      print("Evento 4")
      boton4.config(text="Evento 4 Activo", fg='blue', relief=tk.GROOVE, bg='yellow')
  
  boton1 = ttk.Button(ventana, text="Boton 1", command=evento_uno)
  boton1.grid(row=0, column=0, sticky="nsew", padx=40, pady=40, ipady=40, ipadx=40, columnspan=2)
  
  boton2 = ttk.Button(ventana, text="Boton 2", command=evento_dos)
  boton2.grid(row=1, column=0, sticky="nsew")
  
  ''' boton3 = ttk.Button(ventana, text="Boton 3", command=evento_tres)
  boton3.grid(row=0, column=1, sticky="nsew") '''
  
  boton4 = tk.Button(ventana, text="Boton 4", command=evento_cuatro)
  boton4.grid(row=1, column=1, sticky="nsew")
  
  ventana.mainloop()