PrintGEOG 485 already described some of the fundamental ideas of object-oriented programming and you have been using objects of classes defined in different Python packages like arcpy quite a bit. For instance, you have been creating new objects of the arcpy Point or Array classes by writing something like
p = arcpy.Point() points = arcpy.Array()
You have also been accessing properties of the objects created, e.g. by writing
p.X
... to get the x coordinate of the Point object stored in variable p. And you have been invoking methods of objects, for instance the add(…) method to add a point to the Array stored in variable points:
points.add(p)
What we did not cover in GEOG485 is how to define your own classes in Python, derive new classes from already existing ones to create class hierarchies, and use these ideas to build larger software applications with a high degree of readability, maintainability, and reusability. All these things will be covered in this and the next section and put into practice throughout the rest of this lesson.