Module 7 Exercises

Inheritance

Object Oriented Programming provides a way to reuse software. When you reuse classes you often need to adapt it in a particular way by adding or modifying behavior or data. One way of doing this is to create a new class that extends the existing one using the pattern of inheritance.

Imagine that you have been using the Email class found in the enron.py that has been uploaded to ELMS in Module 7. You would like the class to provide access to the Subject of the email. But you don’t want to change the behavior of the Email class itself because other people are using it already. Write a new class called ExtendedEmail that provides this additional method get_subject().

Composition

When you model things using classes in Object Oriented Programming you often find yourself discovering your classes contain multiple types of things that can also be modeled as classes. When your objects contain other objects you use the pattern of composition to define your classes.

Download pizza.py that has been uploaded to ELMS in Module 7. The Pizza class is being used by a restaurant that doesn’t like to put more than 7 toppings on pizzas. Update the add_topping() method to print out a warning when a user tries to add more than 7 toppings.