default set to boolean True and help set to string 'Tells Django to NOT prompt the user for input of any kind.'. call the parser.add_argument with string '--addrport', default set to an empty string and help as string 'Port number or ipaddr:port to run the server on.'.
parser . add_argument ( '--addrport' , default = '' , help = 'Port number or ipaddr:port to run the server on.' )