model-view-controller pattern command line the object in question is all about controlandunsurprisinglyobjects of this class are called controllers they are the glue that holds the system togetherand usually the place where the most action takes place here are the control functions from our previous program controller_ functions py def name_in_file(filenamename)if not os path exists(filename)return false return name in read_names(filenamedef get_message(name)if name_in_file('names dat'name)return "welcome back {}!format(namewrite_name('names dat'namereturn "hi {}it is good to meet youformat(nameif __name__ ="__main__"main(sys argv[ ]these are not yet encapsulated in an objectbut at least they are in one place nowlet' proceed with the next part of the systemgrouping functions as we go before we return to them and clean up the parts once request is received and the controller decides what must happen to the requestsome data from the system is needed since we are dealing with the grouping together of code that shares functionalitywe will now grab all the functions that have anything to do with the retrieval of data and place them into function file oftenthe structural representation of data is referred to as data modeland so the part of the program that deals with the data is called the model here are the model functions from our previous program model_ functions py def get_append_write(filename)if os path exists(filename)return '