pls explain this flags use

[Tracubik]

Hi all,
i've found here (http://python-gtk-3-tutorial.readthedocs.org/en/latest/
layout.html#table) this code:

[quote]
If omitted, xoptions and yoptions defaults to 
Gtk.AttachOptions.EXPAND | Gtk.AttachOptions.FILL.
[end quote]

xoptions have 3 flags: EXPAND, FILL, SHRINK

so, how it is supposed to work?
it means that by default xoptions is set to EXPAND true, FILL true, 
SHRINK false?

how it work? "|" is used with bits afaik, so i suppouse the xoptions is 3 
bits?

and the default is 
EXPAND FILL SHRINK
  1      1     0

(or something similar)

so i have

AttachOptions.EXPAND = 100
AttachOptions.FILL   = 010

EXPAND|FILL = 100|010 = 110

is that right? 
so if i want EXPAND *and* FILL i have to make EXPAND *binary or* FILL?

i'm new at this sintassi so i'm trying to guess on my own, pls feel free 
to tell me if i'm wrong and where

thanks and best wishes
Medeo