Python - popup menu in wxPython

import wx

class PopMenu(wx.Menu):

    def __init__(self, parent):
        super(PopMenu, self).__init__()

        self.parent = parent

        # menu item 1
        popmenu = wx.MenuItem(self, wx.NewId(), 'one ')
        self.Append(popmenu)
        # menu item 2
        popmenu2 = wx.MenuItem(self, wx.NewId(), 'two')
        self.Append(popmenu2)

class Example(wx.Frame):

    def __init__(self, *args, **kwargs):
        super(Example, self).__init__(*args, **kwargs)

        self.InitUI()

    def InitUI(self):

        self.Bind(wx.EVT_RIGHT_DOWN, self.OnRightDown)

        self.SetSize((600, 400))
        self.SetTitle('Popup Menu')
        self.Centre()

    def OnRightDown(self, e):
        # show popup menu
        self.PopupMenu(PopMenu(self), e.GetPosition())


def main():

    app = wx.App()
    ex = Example(None)
    ex.Show()
    app.MainLoop()


if __name__ == '__main__':
    main()