text: #!/usr/bin/env python
  # coding: utf-8
  
  # In[12]:
  
  
  class PhoneBook():
      
      def __init__(self):
          self.__entries = {}
      
      def add(self, name, phone_number):
          self.__entries[name] = phone_number
      
      def get(self, name):
          if name in self.__entries:
              return self.__entries[name]
          else:
              return None
      
  book = PhoneBook()
  book.add("Ravi", "123456")
  book.add("Aniketh", "56789")
  # book.__entries = {}  >> doesnt work as it is made private.
  print(book.get("Ravi"))