example operation might be addstudentwhich causes student to be enrolled in the course the student being enrolled would be represented by the appropriate student object instructors would be another kind of objectas well as roomsand even times you can see how successive refinement of these ideas could lead to rather sophisticated model of the information structure of the college as beginning programmeryou're probably not yet ready to tackle college information system for nowwe'll study objects in the context of some simple graphics programming simple graphics programming in order to run the graphical programs and examples in this (and the rest of the book)you will need copy of the file graphics py that is supplied with the supplemental materials using the graphics library is as easy as placing copy of the graphics py file in the same folder as your graphics program(salternativelyyou can place it in system directory where other python libraries are stored so that it can be used from any folder on the system the graphics library makes it easy to experiment with graphics interactively and write simple graphics programs as you doyou will be learning principles of object-oriented programming and computer graphics that can be applied in more sophisticated graphical programming environments the details of the graphics module will be explored in later sections here we'll concentrate on basic hands-on introduction to whet your appetite as usualthe best way to start learning new concepts is to roll up your sleeves and try out some examples the first step is to import the graphics module assuming you have placed graphics py in an appropriate placeyou can import the graphics commands into an interactive python session import graphics next we need to create place on the screen where the graphics will appear that place is graphics window or graphwinwhich is provided by the graphics module win graphics graphwin(notice the use of dot notation to invoke the graphwin function that "lives inthe graphics library this is analogous to when we used math sqrt(xto invoke the square root function from the math library module the graphwin(function creates new window on the screen the window will have the title "graphics window the graphwin may overlap your python interpreter windowso you might have to resize or move the python window to make both fully visible figure shows an example screen view the graphwin is an objectand we have assigned it to the variable called win we can now manipulate the window object through this variable for examplewhen we are finished with windowwe can destroy it this is done by issuing the close command win close(typing this command causes the window to vanish from the screen notice that we are again using the dot notation herebut now we are using it with variable namenot module nameon the left side of the dot recall that win was earlier assigned an object