Newbie: display a frame (that's a class attribute) hangs

[Spendius]

Hello,
I'm just trying the following: 
>from Tkinter import *
>import tkFont
>
>class Displayer():
>  def __init__(self):
>    self.initFrame()
>    print "OK i'm here"
>    mainloop()
>    print "i'm there"
>
>  def initFrame(self):
>    hframe  = Frame(bd=5)
>    [etc...]

I display this window by calling from another script:
>window = Displayer()
I can see the window appear, but then everything hangs (if I remove
the 'mainloop()', nothing appears on my screen). I tried also with
>root = Tk()
>window = Displayer(root) #and modified Displayer '__init__' as well of course
>root.mainloop()

but it doesn't help. What does it stay blocked ? (I don't see the
message "i'm there" in my DOS window) 

I'm using Python 2.2.2 on NT.

Thanks !
Spendius