wx._core.Object:
The base class for most wx objects, although in wxPython not much
functionality is needed nor exposed.
wx._core.Event:
An event is a structure holding information about an event passed
to a callback or member function.
wx._core.CommandEvent:
This event class contains information about command events, which
originate from a variety of simple controls, as well as menus and
toolbars.
wx._core.PyCommandEvent:
wx.PyCommandEvent can be used as a base class for implementing
custom event types in Python, where the event shoudl travel up to
parent windows looking for a handler.