def doLayout(self):
    gridsizer = wx.FlexGridSizer(rows = 2)
    gridsizer.AddGrowableCol (1)
    gridsizer.AddGrowableCol (2)

    count = 6

    buttons_list = [wx.Button (self, id = wx.NewId(), label = "Button " + str(n) ) for n in range (count)]

    gridsizer.Add (buttons_list[0])
    gridsizer.Add (buttons_list[1], flag = wx.EXPAND)
    gridsizer.Add (buttons_list[2], flag = wx.EXPAND)
    gridsizer.Add (buttons_list[3])
    gridsizer.Add (buttons_list[4], flag = wx.EXPAND)
    gridsizer.Add (buttons_list[5], flag = wx.EXPAND)

    self.SetSizer(gridsizer)
    self.Layout()