if I am not wrong wxMenuITem does not support tooltips
is there an easy turn around to show a popup tooltip of help upon mouse focus on a menu item for a sec or 2 ?
You need to realize that wxPython wraps the native widgets of the OS that it is running on, so if that underlying widget does not support the desired behavior, then wxPython will not either.
It should be noted, however, that you would normally update the StatusBar with information about the menu items. That is how the wxPython demo for the menus works. In said demo, there is a binding to wx.EVT_MENU_HIGHLIGHT_ALL that is used to update the StatusBar. You might be able to use that event to add a tooltip. 
Alternatively, you might want to check out FlatMenu, which is a pure Python implementation of the wx.Menus. As such, you can easily add new behavior compared with trying to update something that is a wrapped C++ widget.
how to set wxTooltip or tooltip like on wxMenuItem