type and press enter the application tells you that you selected blue and then displays the menu againas shown in figure - figure - after dis playing your selectionthe applica tion displays the menu again type and press enter the application ends creating stacks using lists stack is handy programming structure because you can use it to save an application execution environment (the state of variables and other attributes of the application environment at any given timeor as means of determining an order of execution unfortunatelypython doesn' provide stack as collection howeverit does provide listsand you can use list as perfectly acceptable stack the following steps help you create an example of using list as stack this example also appears with the downloadable source code as liststack py