def OnMouseMotion(self, evt):
    pos = self.lc.ScreenToClient(wx.GetMousePosition())
item_index, flag = self.lc.HitTest(pos)
tip = self.lc.GetToolTip()
if flag == wx.LIST_HITTEST_ONITEMLABEL:
    tip.SetTip('Some information about ' + self.lc.GetItemText(item_index))
else:
    tip.SetTip('')
evt.Skip()
How to tweak my tooltips in wxpython?