When I try to add a button with loop action in the tree view I get this error :

ValueError: "name 'records' is not defined" while evaluating
u'for rec in records:\n\t\t\t\t\trec.action_update_period_loop()'

and here the source :
  <record id="action_update_period" model="ir.actions.server">
            <field name="name">mettre à jour la periode</field>
            <field name="model_id" ref="account.model_account_payment"/>
            <field name="state">code</field>
            <field name="code">
                for rec in records:
					rec.action_update_period_loop() 
            </field>
        </record>
        
     <record id="ir_update_period" model="ir.values">
            <field eval="'client_action_multi'" name="key2"/>
            <field eval="'account.payment'" name="model"/>
            <field name="name">mettre à jour la periode</field>
            <field eval="'ir.actions.server,%d'%action_update_period" name="value"/>
        </record> 
please help me fix this error and thanks in advance