ΘΕΜΑ: tkinter και κουμπί ENTER

#!/usr/bin/python3
from tkinter import *
from tkinter.messagebox import *
 
class forma(Frame):
 
	def enter_stoixeia(self):
 
 
		self.label_onoma = Label(self, text = 'Ονοματεπώνυμο')
		self.label_onoma.pack()
		self.enter_onoma = Entry(self)
		self.enter_onoma.pack()
 
 
 
		self.label_tilefono = Label(self, text = 'Τηλέφωνο')
		self.label_tilefono.pack()
		self.enter_tilefono = Entry(self)
		self.enter_tilefono.pack()
 
 
 
		self.label_mail = Label(self, text = 'mail')
		self.label_mail.pack()
		self.enter_mail = Entry(self)
		self.enter_mail.pack()
 
 
 
		self.label_odos = Label(self, text = 'Διεύθυνση')
		self.label_odos.pack()
		self.enter_odos = Entry(self)
		self.enter_odos.pack()
	def drawGUI(self):
		self.enter_stoixeia()
		self.enter_onoma.focus()
		return root;
	def OK(self):
		self.koumpi = Button(self, text = 'OK')
		self.koumpi.pack()
	def __init__(self, master = None):
		Frame.__init__(self, master)
		self.master.title("Αντζέτα")
		self.pack()
		self.drawGUI()
		self.OK()
 
root = Tk()
app = forma(master = root)
app.mainloop()