class Start:
        def __init__(self):
                self.Bind(EVT_CHOOSE, self.listChose)

        def listeChoix(self,evt):
                urls = evt.urls
                titles = evt.titles
                print urls
                print titles
                object_s = wx.SingleChoiceDialog(self, labelO, labelV, titles, wx.CHOICEDLG_STYLE)
                if object_s.ShowModal() == wx.ID_OK:
                        title = object_s.GetStringSelection()
                        url = urls[titles.index(title)]
                        object_s.Destroy()
                else:
                        object_s.Destroy()
                        error = wx.MessageDialog(self,errorChose,TitleError,wx.ICON_ERROR|wx.OK)
                        error.ShowModal()
                        return

        def onPushButton(self):
                self.v_search = Search(self,self.url.GetValue())
                self.v_search.start()

class Search:
    ...
    if len(urls) > 1:
         evt = Choose(urls = urls, titles = titles)
         wx.PostEvent(self.parent, evt)
         return None,None