Interface pour programme python

#! /usr/bin/python3
from tkinter import *

def decodeString():
        mess.delete(0, END)
        mess.insert(0, "DECODED! with key " + key.get()) 
        print("DECODED!")
        
def encodeString():
        coded.delete(0, END)
        coded.insert(0, "ENCODED! with key " + key.get())
        print("ENCODED") 
master = Tk()

Label( master, text = "Message:" ).grid(row=0)
mess = Entry(master)
Label(master, text="Message Codé:").grid(row=1)
coded = Entry(master)
Label( master, text = "Key:" ).grid(row=2)
mess = Entry(master)
key = Entry(master)

mess.grid(row=0, column=1)
coded.grid(row=1, column=1)
key.grid(row=2, column=1)

encode = Button(master, text="Encode string", command=encodeString).grid(row=3, column=1, sticky=W, pady=4)
decode = Button(master, text="Decode string", command=decodeString).grid(row=3, column=2, sticky=W, pady=4)

mainloop()