action set to 'append', default is a list containing string 'py' and help set to string: 'The file extension(s) to render (default: "py"). Separate multiple extensions with commas, or use -e multiple times.'. call the method parser.add_argument with 6 arguments: string '--name', string '-n', dest set to string 'files',
parser . add_argument ( '--name' , '-n' , dest = 'files' , action = 'append' , default = [ ] , help = 'The file name(s) to render. ' 'Separate multiple extensions with commas, or use ' '-n multiple times.' )