When I scroll with my mousewheel, it draws many intermediate steps, and I want it to only draw the immediate destination. It's a bit laggy otherwise.
I tried intercepting wx.EVT_MOUSEWHEEL with event.StopPropagation() and doing .Scroll() manually, but it still scrolls by itself, StopPropagation() doesn't work.
The version of wxPython is 2.9. The widget is wx.ScrolledWindow.
You can use the following to adjust the size of a scroll event:    

SetScrollRate(self, xstep, ystep)
  Set the horizontal and vertical scrolling increment only.
See the pixelsPerUnit parameter in SetScrollbars .
Parameters:
  xstep (int) –
  ystep (int) –

Coupled with the font size and the number of items in the window, this can of course be variable.
Note:

StopAutoScrolling(self)
  Stop generating the scroll events when mouse is held outside the window

and:    

StopPropagation(self)
Stop the event from propagating to its parent window.

Not stop the event itself
How to disable smooth scrolling in wxPython?