Week 2: Object Oriented Programming

Outcomes

• Write or identify a definition for
• Functions
• Methods
• Class
• Object
• Encapsulation
• Abstraction
• Inheritance
• Polymorphism
• Constructor
• __init__
• Override(s)
• Magic Methods
• Subclass
• Superclass
• Read class-based pseudocode and explain/identify the goal of the code [Continued from last week]
• Read existing Python code and connect it to corresponding pseudocode [Continued from last week]

 

Activities

• Schafer's Videos - Getting Started with Object Oriented Programming
  • If you care, here are the PowerPoint Slides from the videos
  • Motivating Object Oriented Programming [Video, 6 minutes]
  • The Concepts and Vocabulary of Objects [Video, 20 minutes]
    • There is a lot of detail in here.
      • Focus on the big picture and the general meaning behind the four pillars.
      • Come to an understanding on the vocabulary of the four pillars.
    • But don't worry about being a detailed expert.
  • Looking at code for the a Python class, version 1
    • Walkthrough video [Video, 26 minutes]
    • CreditCard.py [Code, a typical Python class]
    • WalletRunner.py [Code, a simple program that uses several instances of the Credit Card class.
  • Modifying the CreditCard to explain the idea behind magic methods
    • Walkthrough video [Video, 12 minutes]
    • MagicCreditCard.py [Code]
    • List of Magic Methods
  • The Fraction Class (different code from what will be in your textbook. Same basic idea)
    • Walkthrough video [Video, 14 minutes]
    • Schafer's version of Fraction.py [Code]
    • Slightly ImprovedFraction.py [Code]

• Textbook Reading
  • Section 1.13.1
    • This is long and detailed
    • But it covers most everything you need to know about objects
  • Section 1.13.2
    • This starts to get a bit more confusing.
    • The semi-important aspect of this is the concept of inheritance and not the actual implementation of the inheritance in the Logic Gates example.
      • Pay attention to the discussions about inheritance more than any code itself.
      • Cross reference this with the discussion about inheritance from my videos above.

• Checking your understanding of OOP vocabulary
  • Consider a couple of non-programming scenarios that model OOP pillars.
  • My answer key.

• You Do It (YDI) Activity #2
• Activity Part 1 (for all) - Consider what a Python Class for a Scratch Sprite would do/look like
• Activity Part 2 (optional) - Create/write the Python Class code for the design created in part 1
  • I will repeat, I do NOT expect you to be able to write a Python class as an outcome of this course.
  • But some of you might be interested in trying. This is your opportunity to TRY.
  • My solution is below.
• Activity Part 3 (for all) - Examine my solution code and consider how this code provides what we built in Part 1

Additional Resources

• If you think you are starting to get it but you want to hear it ONE MORE TIME from a different source, consider the following resources I really like:
  • How to Explain OOP to a 6 year old.
    • A good article to revisit the 4 pillars of Object Oriented Programming
  • Object Oriented Programming in 7 minutes video
    • You may want to turn on the closed captioning
  • Grab the book you used in FCCS
    • Read pp 350-356
 

• You may have noticed this on the table of contents page for your textbook. Professor Gerry Jenkins is a retired professor from Long Beach City College who made a bunch of videos to correspond with the readings in your textbook. I have NOT viewed all of them. But, I know how helpful it can be to have a wide variety of study resources.
  • Videos 15 - 20 on this playlist correspond to material we covered this week. (To be more accurate, 15-17 align with our course. Videos 18-20 go into deeper detail on things mostly beyond the scope of this course.
• If you find this information about programming languages interesting you might grab your book from FCCS and read pp 306-316 to read about the evolution and different types of of computer programming languages
  • For this course we are most interested in the material on OOP on pp 315-316
  • Having said that, the material on 306-314 is stuff that you might read in the big picture of things.