# -*- encoding:Utf8 -*-

from tkinter import *
from math import *

class Calculatrice(Tk):

    def __init__(self):
        Tk.__init__(self)
    
        entree = Entry(self, bd = 2, relief = GROOVE)
        entree.bind("<Return>", self.evaluer)
        entree.pack(padx = 10, pady = 5)

        self.chaine = Label(self)
        self.chaine.pack(padx = 10, pady = 5)

    def evaluer(self, event):
        self.chaine.configure(text = "Résultat = {}"
                              .format(eval(self.entree.get())))


# ----- Corps principal du programme: -----

calculette = Calculatrice()

calculette.mainloop()