Python help

Hello, im just started with python and i already have a problem. I’ve this script:

# File: hello1.py

from Tkinter import *

root = Tk()

w = Label(root, text="Hello, world!")
w.pack()

root.mainloop()

A tutorial says, this need to create a window, but it dont! Anyone can help me?

P.S. the tutorial: http://www.pythonware.com/library/tkinter/introduction/hello-tkinter.htm