The wxPython tutorial

http://www.zetcode.com/wxpython/tips/self.sheet1 = MySheet(self)self.sheet1.SetNumberRows(55)self.sheet1.SetNumberCols(25)for i in range(self.sheet1.GetNumberRows()):self.sheet1.SetRowSize(i, ID_ROWSIZE)self.sheet1.SetFocus()box.Add(self.sheet1, 1, wx.EXPAND)self.CreateStatusBar()self.Centre()self.Show(True)def OnUndo(self, event):if len(stockUndo) == 0:returna = stockUndo.pop()if len(stockUndo) == 0:self.toolbar.EnableTool(ID_UNDO, False)a.undo()stockRedo.append(a)self.toolbar.EnableTool(ID_REDO, True)def OnRedo(self, event):if len(stockRedo) == 0:returna = stockRedo.pop()if len(stockRedo) == 0:self.toolbar.EnableTool(ID_REDO, False)a.redo()stockUndo.append(a)self.toolbar.EnableTool(ID_UNDO, True)def OnQuitNewt(self, event):self.Close(True)app = wx.App()Newt(None, -1, 'Newt')app.MainLoop()stockUndo = []stockRedo = []There are two list objects. stockUndo is a list that holds allchanges, that we can undo. stockRedo keeps all changes,that can be redone. The changes are instantiated into aUndoText object. This object has two methods. undo andredo.9 de 15 27/04/2008 1:09