When to use api.one and api.multi in odoo | openerp?

Question

Recently odoo (formerly OpenERP) V8 has been released. In new API method decorators are introduced. in models.py methods needs to be decorated with @api.one

Answer 1

@api.one:

This decorator loops automatically on Records of RecordSet for you. Self is redefined as current record:

@api.one
def func(self):
    self.name = 'xyz'

@api.multi:

Self will be the current RecordSet without iteration. It is the default behavior:

@api.multi
def func(self):
    len(self)

For the detailed description of all API you can refer this Link