phonebook.py

class PhoneBook:

    def __init__(self, city_name):
        self.city_name = city_name
       	self.store = {}

    def store_number(self, name, number):
       	print 'Storing number for city: ' + self.city_name
        self.store[name] = number

    def retrieve(self, name):
        return self.store.get(name)


sydney_phone_book = PhoneBook('Sydney')
melbourne_phone_book = PhoneBook('Melbourne')

sydney_phone_book.store_number('Sarah', '123456')
melbourne_phone_book.store_number('Steven', '654321')
sydney_phone_book.store_number('Bob', '1111111')