frame.grid(column=0, row=0, sticky=(N, S, E, W))
valores = StringVar()
valores.set(
    'Carro Coche Moto Bici Triciclo Patineta Patin Patines Lancha Patrullas')
lstbox = Listbox(frame, listvariable=valores, selectmode=MULTIPLE, width=20,
    height=10)
lstbox.grid(column=0, row=0, columnspan=2)

def select():
    reslist = list()
seleccion = lstbox.curselection()
for i in seleccion:
    entrada = lstbox.get(i)
reslist.append(entrada)
for val in reslist:
    print(val)
btn = ttk.Button(frame, text='Choices', command=select)
btn.grid(column=1, row=1)
main.mainloop()
Python Tkinter multiple selection Listbox