Hello Timo,

For that I use to create a many2one field in the model pointing to a new model whose instances are the values that I want to allow.

Let's say that you have a partner and you want to add a select input whose values can be dinamically generated. Then you can create the following field into the res.partner:

'x_partner_type_id': fields.many2one(
    'mycompany.customer.type',
    'Partner Type',
    required=True,
    ondelete='restrict',
),

Then, you will have to create the model mycompany.customer.type where you will have all the choices:

from openerp.osv import fields, osv

class customer_type(osv.Model):
    _name = 'mycompany.customer.type'
    _columns = {
        'name': fields.char('Name', size=64, required=True),
        'description': fields.text('Description'),
    }

customer_type()

And that's it. Now you have a field in your partner whose values are generated dinamically by using your view (you have to add x_partner_type_id into partner's view).