Hi,

Try this code.
In the xml
<?xml version="1.0" encoding="utf-8"?>
<odoo>
  <data noupdate="1">
    <record id="partner_sequence_id" model="ir.sequence">
      <field name="name">Partner Sequence</field>
<field name="code">partner_sequence_code</field>
      <field name="prefix">PAR/</field>
      <field name="padding">0</field>
      <field name="number_next">1</field>
    </record>


In the py

@api.model
def create(self, vals):
vals['name'] = self.env['ir.sequence'].next_by_code('partner_sequence_code')
    return super(MyModel, self).create(vals)



Hope it helps