Object Oriented Programming

Reading

Chapter 17.

Key ideas

From chapter 17

• An instance of a class is mutable.
• A mutator method is a method of a class that changes the values of one or more instance variables.
• Shallow equality occurs when two variables refer to the same object in the computer’s memory. The Python keyword is tests for shallow equality.
• Deep equality occurs when either there is shallow equality OR two variables refer to objects that contain the same underlying (significant) values.
• The method __add__(self, other) can be defined so that the operator + can be used.

Additional resources

In this course, we did not cover inheritance, which is a very useful feature of object oriented programming. If you would like to read about it, check out this short reading. You can also watch the lectures from the Spring 2019 CSCI 127 course which address inheritance:

• Ineritance 1
• Inheritance 2
• Inheritance 3

You can download the dungeons.py file for an example of inheritance.

If you’d like to test your knowledge, here is an example question using inheritance.