Thanks Hilar, sorry for my poor coding skill, the python showed me "AttributeError: 'int' object has no attribute 'unlink()

Am I suppose to import some library that support the method unlink()?

logging.info('Creating warehouse routes ...')

odoo = get_session()

wh_route_obj = odoo.env['stock.location.route']

config = {}

config['name'] = 'Manufacture'

config['sequence'] = 5

val = wh_route_obj.create(config)

val.unlink

Another is what if I want to delete the default value that created in unknown module? How I can unlink it without know where the code is? 

Thanks alot for you answer just now, it take a step for me to understand odoo configuration, sorry for cannot do comment in your answer due to not enough karma point.