Hi, I want to use editable choice editor with PyGridTableBase. When I edit a cell it is crashing What is error in my code? My python code:

import wx
import wx.grid as gridlib

class MyTableBase(gridlib.PyGridTableBase):

   def __init__(self):
       gridlib.PyGridTableBase.__init__(self)

       self.data = {0:["value 1", "value 2"],
                    1:["value 3", "value 4", "value 5"]}

       self.column_labels = [unicode(u"Label 1"),
                             unicode(u"Label 2"),
                             unicode(u"Label 3")]



       self._rows = self.GetNumberRows()
       self._cols = self.GetNumberCols()

   def GetColLabelValue(self, col):
       return self.column_labels[col]

   def GetNumberRows(self):
       return len(self.data.keys())

   def GetNumberCols(self):
       return len(self.column_labels)

   def GetValue(self, row, col):
       try:
           if col > self.GetNumberCols():
               raise IndexError
           return self.data[row][col]
       except IndexError:
           return None

   def IsEmptyCell(self, row, col):
       if self.data[row][col] is not None:
           return True
       else:
           return False

   def GetAttr(self, row, col, kind):
       attr = gridlib.GridCellAttr()
       editor = gridlib.GridCellChoiceEditor(["xxx", "yyy", "zzz"],
                                             allowOthers = True)
       attr.SetEditor(editor)
       attr.IncRef()
       return attr

class MyDataGrid(gridlib.Grid):
   def __init__(self, parent):
       gridlib.Grid.__init__(self, parent, wx.NewId())
       self.base_table = MyTableBase()
       self.SetTable(self.base_table)


if __name__ == '__main__':
   app = wx.App(redirect = False)
   frame = wx.Frame(None, wx.NewId(), title = u"Test")
   grid_ = MyDataGrid(frame)
   frame.Show()
   app.MainLoop()