default set to None, help is a string 'Only look for fixtures in the specified app.'. call the method parser.add_argument with 6 arguments: string '--ignorenonexistent', string '-i', action as a string 'store_true',
parser . add_argument ( '--ignorenonexistent' , '-i' , action = 'store_true' , dest = 'ignore' , default = False , help = 'Ignores entries in the serialized data for fields that do not ' 'currently exist on the model.' )