graphical programming is lot of fun and provides great vehicle for learning about objects in the processyou will also learn the principles of computer graphics that underlie many modern computer applications most of the applications that you are familiar with probably have so-called graphical user interface (guithat provides visual elements like windowsicons (representative pictures)buttonsand menus interactive graphics programming can be very complicatedentire textbooks are devoted to the intricacies of graphics and graphical interfaces industrial-strength gui applications are usually developed using dedicated graphics programming framework python comes with its own standard gui module called tkinter as gui frameworks gotkinter is one of the simplest to useand python is great language for developing real-world guis stillat this point in your programming careerit would be challenge to learn the intricacies of any gui frameworkand doing so would not contribute much to the main objectives of this which are to introduce you to objects and the fundamental principles of computer graphics to make learning these basic concepts easierwe will use graphics library (graphics pyspecifically written for use with this textbook this library is wrapper around tkinter that makes it more suitable for beginning programmers it is freely available as python module file and you are welcome to use it as you see fit eventuallyyou may want to study the code for the library itself as stepping stone to learning how to program directly in tkinter the object of objects the basic idea of object-oriented development is to view complex system as the interaction of simpler objects the word objects is being used here in specific technical sense part of the challenge of oo programming is figuring out the vocabulary you can think of an oo object as sort of active data type that combines both data and operations to put it simplyobjects know stuff (they contain data)and they can do stuff (they have operationsobjects interact by sending each other messages message is simply request for an object to perform one of its operations consider simple example suppose we want to develop data processing system for college or university we will need to keep track of considerable information for starterswe must keep records on the students who attend the school each student could be represented in the program as an object student object would contain certain data such as nameid numbercourses takencampus addresshome addressgpaetc each student object would also be able to respond to certain requests for exampleto send out mailingwe would need to print an address for each student this task might be handled by printcampusaddress operation when particular student object is sent the printcampusaddress messageit prints out its own address to print out all the addressesa program would loop through the collection of student objects and send each one in turn the printcampusaddress message objects may refer to other objects in our exampleeach course in the college might also be represented by an object course objects would know things such as who the instructor iswhat students are in the coursewhat the prerequisites areand when and where the course meets one see appendix for information on how to obtain the graphics library and other supporting materials for this book