old_contents: class Singleton(object):
      def __new__(cls, *a, **k):
          if not hasattr(cls, '_inst'):
              cls._inst = super(Singleton, cls).__new__(cls, *a, **k)
              return cls._inst
  
      def __init__(self, *args, **kwargs):
         pass
  
     def 
  
new_contents: #! /usr/bin/python
  # -*- coding: utf-8 -*-
  '''
  Singleton Pattern
  Author: Kei Nakata
  Data: Oct.6.2014
  '''
  
  class Singleton(object):
      def __new__(cls, *a, **k):
          if not hasattr(cls, '_inst'):
              cls._inst = super(Singleton, cls).__new__(cls, *a, **k)
          return cls._inst
  
      def __init__(self, *args, **kwargs):
         pass
  
      def setString(self, msg):
         self.msg = msg
  
      def printString(self):
         print self.msg
  
  if __name__ == '__main__':
      A = Singleton()
      B = Singleton()
      A.setString("Hello")
      A.printString()
      B.setString("Bye")
      A.printString()
  
subject: Add comments to Singleton.py