How to remove a tooltip in wxpython?

Question

How do I remove a tooltip in wxpython? I know they have an expiry time after which they disappear but I'm struggling to find anything in the docs about purposefully removing them.

In my particular situation, I have a wx.grid which on wx.EVT_MOTION calls a function, that gets the coordinates of the event in the grid, finds out which cell it is (a la grid.CalcUnscrolledPosition() and grid.XYToCell()) and then, provided it is a particular cell, creates a tooltip. Now, in the case there is a tooltip already, I want to remove it if the cursor hovers above a cell that doesn't require a tooltip. I'm struggling to find anything in the documentation. This link has the ToolTip.Enable() function, but that has no result whatsoever. The docs seem to imply that it should enable/disable tooltips globally but nothing happens.

Any ideas?

FYI, Win7, Python 2.7.9, wx 3.0.2.0

EDIT Rough structure of relevant code:

self.grid.GetGridWindow().Bind(wx.EVT_MOTION, self.onMouseOver)

...

def onMouseOver(self, event):
    #get current grid cell
    x, y = self.grid.CalcUnscrolledPosition(event.GetX(), event.GetY())
    coords = self.grid.XYToCell(x,y)
    row = coords[0]
    col = coords[1]

    if col in relevanCols:
        event.GetEventObject().SetToolTipString("Hai")
    else:
        self.grid.SetToolTip(None)

    event.Skip()

Answer 1

Finally, after beasting the damned thing for an age, a result and mind bogglingly simple as well SetToolTip(None)
See below:

import wx
class MyForm(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, wx.ID_ANY, "Toggle")
        self.panel = wx.Panel(self, wx.ID_ANY)
        self.dummy = wx.StaticText(self.panel, -1, "")
        self.cb1 = wx.CheckBox(self.panel, -1,"Choice 1", pos=(10,10))
        self.cb2 = wx.CheckBox(self.panel, -1,"Choice 2", pos=(10,40))
        self.cb1.Bind(wx.EVT_CHECKBOX, self.onToggle1)
        self.cb2.Bind(wx.EVT_CHECKBOX, self.onToggle2)
        self.cb1.SetToolTipString(wx.EmptyString)
        self.cb2.SetToolTipString(wx.EmptyString)
    #----------------------------------------------------------------------
    def onToggle1(self, event):
        if self.cb1.GetValue() == True:
            self.cb1.SetToolTipString("Check Box 1 is Checked")
        else:
            self.cb1.SetToolTip(None)

    def onToggle2(self, event):
        if self.cb2.GetValue() == True:
            self.cb2.SetToolTipString("Check Box 2 Is Checked")
        else:
            self.cb2.SetToolTip(None)

# Run the program
if __name__ == "__main__":
    app = wx.App(False)
    frame = MyForm()
    frame.Show()
    app.MainLoop()

Edit: For the code in your question in relation to use in a grid, change the

if col in relevanCols:
    event.GetEventObject().SetToolTipString("Hai")
else:
    self.grid.SetToolTip(None)

to:

if col in relevanCols:
    event.GetEventObject().SetToolTipString("Hai")
else:
    event.GetEventObject().SetToolTip(None)