Hi folks,
FYI, the standard menu does not appear when opening a frame/window under Ubuntu 16.04 (the latest version).
http://askubuntu.com/questions/762137/applications-menu-missing-from-menu-bar
When opening wxPython demo demo.py the menu will be missing - until you expand to full screen and click on the title bar.
I don’t believe it has been fix as of today - but I think the same happens to any GTK program.
Johnf