# -*- coding: utf-8 -*- # lp4all: literate programming embedded in source code as wiki comments # Copyright (C) 2006 Jean-Marie Favreau, Frédéric Lehobey, David Mentré # and Thomas Petazzoni # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
class Singleton: _singleton = None def getSingleton(cls): if not isinstance(cls._singleton, cls): cls._singleton = cls() return cls._singleton getSingleton = classmethod(getSingleton)
Base class to implement the Singleton design pattern. It allows to ensure that derivative classes have only one instance. See Wikipedia for more information about the Singleton design pattern.