# 1 - There are mostly 2 ways of setting a default value for the fields in Odoo(there are more, but this are the most used ones).
#old api
_defaults = {
'ship': 'ship_value1',
}
#new api
ship = fields.Selection([('ship_value1', 'Value1'),('ship_value2', 'Value2')], default='ship_value1')
# 2- Setting the value in xml view field or action of the form that contains the field, using context ('default_ship') like:
#the content of the field lines is not necessary, i put it for the sake of the example
<field name='lines' context="{'default_ship': 'ship_value1'}">
<form string="Line">
<field name="ship"/>
</form>
<tree>
<field name="ship"/>
</tree>
</field>