An Introduction to Object-Oriented Programming

Although often used as a "scripting" language, Python is an object-oriented programming language at its core. This tutorial is designed for programmers who are familiar with Python yet new to the concept of object-oriented programming. We also welcome programmers who are experienced with other object-oriented languages yet new to Python.

We will begin the tutorial by introducing the general principles of object-oriented programming. We then focus on Python's treatment of object orientation. The tutorial will be organized as a mix of formal presentations together with hands-on demonstrations and exercises.

Take your Python programming to the next level!

Presenters

Drs. Goldwasser and Letscher are Faculty Members in the Department of Mathematics and Computer Science at Saint Louis University and authors of the book Object-Oriented Programming in Python. They have been instrumental in the development of SLU's Python-based introductory programming course and are winners of the Jim Korn Award for Scholarship of Teaching and Learning at SLU. Components of their curriculum have been presented at national and international conferences on Computer Science Education and within the main program of PyCon 2008.

Requirements

Minimally, attendees should have basic familiarity with core programming concepts (e.g., variables, control structures, functions).

Attendees should bring laptops with Python installed (version 2.3 or later) if they want to work through the examples.

Outline

The Object-Oriented Paradigm

The pairing of data and behavior

Encapsulation

Accessors vs. mutators

Inheritance hierarchies

Using Objects

The built-in list class as a typical example of a mutable type.

The built-in str class as a typical example of an immutable type.

Numeric types and operators

Defining Your Own Classes

Example: A simple Point class

Example: A more robust Point class

Example: a Television class

Example: a Fraction class

Good Software Practices

Case Study: a Mastermind game

Top-level design; bottom-up implementation

Naming conventions

Python docstrings

Encapsulation

Unit testing

Break -- refreshments served

Inheritance

Providing new methods

Overriding existing methods

Example: A DeluxeTV

Example: A SortedSet

Multiple inheritance

When should inheritance (not) be used?

A Deeper Understanding of the Management of Objects

Understanding objects and references

Aliasing

Equivalence testing

Objects that reference other objects

Deep vs. shallow copying

Parameter passing

Default parameter values

Python's Internal Mechanisms

id, type, isinstance

Python's use of dictionaries (dir, locals, globals, vars)

Name resolution in an object-oriented framework (local, instance-level, class-level, parent-level namespaces).

Structural recursion

Our own (recursive) list implementation