creating class variables class variables provide global access to data that your class manipulates in some way in most casesyou initialize global variables using the constructor to ensure that they contain known good value the following steps demonstrate how class variables work open python shell window you see the familiar python prompt type the following code (pressing enter after each line and pressing enter twice after the last line)class myclassgreeting "def sayhello(self)print("hello { }format(self greeting)this is version of the code found in the "working with constructorssection of the but this version doesn' include the constructor normally you do include constructor to ensure that the class variable is initialized properly howeverthis series of steps shows how class variables can go wrong type myclass greeting "zeldaand press enter this statement sets the value of greeting to something other than the value that you used when you created the class of courseanyone could make this change the big question is whether the change will take type myclass greeting and press enter you see that the value of greeting has changedas shown in figure - type myinstance myclassand press enter python creates an instance of myclass named myinstance figure - you can change the value of greeting