from tkinter import *
import os

root=Tk()
root.geometry('350x100')
root.title("Spegnimento automatico")
root.resizable(0,0)

def shutdown():
    sec=v.get()
    os.system('shutdown -s -t', sec)

def shutdownFalse():
    os.system('shutdown -a')

mLabel=Label(text="Inserisci Tempo in secondi")
mLabel.place(x= 100, y=0)
v=StringVar()
mEntry=Entry(root, textvariable=v)
mEntry.place(x= 110, y= 25)
mButton=Button(text= 'Conferma', command= shutdown)
mButton.place(x=90, y=50)
mButtonFalse=Button(text= "Annulla", command= shutdownFalse)
mButtonFalse.place(x=210, y=50)

root.mainloop()