ABSTRACT

As customary when using mainstream Object-Oriented Programming (OOP) languages, including Python, the example program uses classes to define the capsules of data and procedures. Classes are templates for the construction of objects. As mentioned before, even though the most popular OOP languages lead us to believe that classes are central to OOP, the fact is that they are neither necessary nor sufficient for programming in the Things style. Inheritance is another concept that has made it to all mainstream OOP languages. The example program uses inheritance in a somewhat artificial manner, simply for illustration purposes. In the example, an abstract base class called TFExercise is defined. Object-oriented programming was first introduced by Simula 67 in the 1960s. Simula 67 already had all the main concepts explained above, namely objects, classes and inheritance.