nl: call the method parser.add_argument with 5 arguments: string '--database', action set to string 'store', dest as a string 'database',
code: parser . add_argument ( '--database' , action = 'store' , dest = 'database' , default = DEFAULT_DB_ALIAS , help = 'Nominates a database to ' 'introspect. Defaults to using the "default" database.' )