Simple Tk text file reader

gistfile1.py

from Tkinter import *
import tkFileDialog

main = Tk()
main.title("Notpad")
main.minsize(width=500,height=400)

text = Text(main)
text.pack(expand=YES, fill=BOTH) 

def doOpen():
    the_file = tkFileDialog.askopenfile(mode='r')
    text.insert(0.0, the_file.read())

button = Button(main, text="Open file", command=doOpen)
button.pack()
main.mainloop()