@Moytaba they are expecting you to built the script in a way that it itself loops over the command-line arguments (which is a good practice and should be the standart behaviour!) – take a look at
sys.argv. first test whether there are any arguments (and throw an error if not), then loop over them calling the
summaryfile
function for every single one. if the arguments need to be existing files, test for that as well inside the loop.