all, I want to draw a rectangular or a container with 20 slots inside. it is like a cd container or archive, with empty slot to insert the cd or book. I choose wxPython. 
for this 20 horizontal empty slots, i see there is wx.BoxSizer(wx.Horizonal) or other sizers to make the layout.
my question is, Is it possible to have "visible border and grey background" (to represent the empty slots) for the spaces generated by the wx.BoxSizer? It seems to me that, it is not possible. The sizer seems only to do layout, instead of generating visible subwindow.
If it is not possible, I think I need to create a slot window class for this "border and colorful background" feature, and create 20 slot window objects and add into the sizer. Then, I have to use create another window class to represent the book or CD, and insert this CD window to the slot window. 
This sounds a bit awkard. I do not know if slot window is necessary or maybe wx.sizer (or other sizer) could achieve the same effect as the slot window.
I would create a subclass of wx.Panel for each "slot", then manage them with a grid or box sizer.
use wxPython to draw a grided rectangular container or box