This book introduces the terminology of the object-oriented paradigm. It focuses on objectoriented design with step-by-step examples. It guides us from simple inheritance, one of the most useful tools in the object-oriented programmer's toolbox, through exception handling to design patterns, an object-oriented way of looking at object-oriented concepts. Along the way, we'll learn how to integrate the object-oriented and the not-so-objectoriented aspects of the Python programming language. We will learn the complexities of string and file manipulation, emphasizing the difference between binary and textual data. We'll then cover the joys of unit testing, using not one, but two unit testing frameworks. Finally, we'll explore, through Python's various concurrency paradigms, how to make objects work well together at the same time.