Singleton on Python

I released Singleton with wiki ()

my code:

   class   spritemanager  ( object ):   def   __ New __  ( class ):   if   not   hasttr  (cls,  'Instance' ):  class.instance =  super  (spritemanager) .__ New __ (CLS)   retu  cls.instance  def   __ init __  ( self ):  self.setsprite =  set  ()     
 every time you call  spritemanager ()  constructs are called. According to the Singleton concept, initialization should take place once at the first call. How to make the designer call once?