How to size master?

[Wayne]

Hello,
Can somebody tell be how to size the top-level widget? For example

from Tkinter import *
class App:
        def __init__(self, master):
              L1 = Label(...............stuff)

How would I give master a heigth and width? I remember reading how  to
do this, but
I can't seem to find it now .
TIA.
Wayne