I want to make a transparent BACKGROUND frame with my python app (WxPython)

I've always wanted to make a app that's transparent, I love how it looks. I tried to make on of my apps transparent with the SetTransparent(alpha), but I bumped into a big problem.

Yes it makes my app transparent (^。^), but it makes EVERYTHING transparent (=。=).

I have no idea how to fix this problem. Hours of research didn't really help out.

What I meant by background is, nothing else but the literary background of the app. not the button, not the status bar, not the title, just the background. for instance if i wanted the background alpha being 250 i want the buttons to look like there floating.

Example:

import wx
app = wx.App()
win=wx.Frame(None, -1, 'Simple', size=(800,600), style= wx.SYSTEM_MENU | wx.CAPTION | wx.CLOSE_开发者_开发技巧BOX)
win.SetTransparent(200)

win.Show()
app.MainLoop()