myslice/util/singleton.py

   1 #-------------------------------------------------------------------------
   2 # Class Singleton
   3 #
   4 # Classes that inherit from Singleton can be instanciated only once
   5 #-------------------------------------------------------------------------
   6
   7 class Singleton(type):
   8     def __init__(cls, name, bases, dic):
   9         super(Singleton,cls).__init__(name,bases,dic)
  10         cls.instance=None
  11
  12     def __call__(cls, *args, **kw):
  13         if cls.instance is None:
  14             cls.instance=super(Singleton,cls).__call__(*args,**kw)
  15         return cls.instance
  16
  17
  18 # See also
  19 # http://stackoverflow.com/questions/6760685/creating-a-singleton-in-python