new_contents: #! /usr/bin/python
  # -*- coding: utf-8 -*-
  '''
  Proxy Pattern
  Author: Kei Nakata
  Data: Oct.6.2014
  '''
  import abc
  
  class Subject(object):
      __metaclass__ = abc.ABCMeta
      @abc.abstractmethod
      def show(self):
          pass
  
  class ConcreteSubject(Subject):
      def show(self):
          print "Hello World"
  
  class Proxy(Subject):
      def __init__(self):
          self.concrete_subject = None
  
      def show(self):
          if(self.concrete_subject == None):
              self.concrete_subject = ConcreteSubject()
          self.concrete_subject.show()
  
  
  if __name__ == '__main__':
      a = Proxy()
      a.show()
  
subject: Add Proxy.py