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