default is boolean False and help is a string 'Use natural keys if they are available (deprecated: use --natural-foreign instead).'. call the method parser.add_argument with 5 arguments: string '--natural-foreign', action set to string 'store_true',
parser . add_argument ( '--natural-foreign' , action = 'store_true' , dest = 'use_natural_foreign_keys' , default = False , help = 'Use natural foreign keys if they are available.' )