Modulo que gestiona las notas de credito generadas desde la factura

class account_invoice(osv.osv):
    _inherit = 'account.invoice'

    def _refund_cleanup_lines(self, cr, uid, lines):
        for line in lines:
            del line['id']
            del line['invoice_id']
            if 'account_id' in line:
                line['account_id'] = line.get('account_id', False) and line['account_id'][0]
            if 'product_id' in line:
                line['product_id'] = line.get('product_id', False) and line['product_id'][0]
            ######################
            if 'concept_retention_ica' in line:
                line['concept_retention_ica'] = line.get('concept_retention_ica', False) and line['concept_retention_ica'][0]
            if 'concept_retention_iva' in line:
                line['concept_retention_iva'] = line.get('concept_retention_iva', False) and line['concept_retention_iva'][0]
            if 'concept_retention_rete' in line:
                line['concept_retention_rete'] = line.get('concept_retention_rete', False) and line['concept_retention_rete'][0]
            ######################
            if 'uos_id' in line:
                line['uos_id'] = line.get('uos_id', False) and line['uos_id'][0]
            if 'invoice_line_tax_id' in line:
                line['invoice_line_tax_id'] = [(6,0, line.get('invoice_line_tax_id', [])) ]
            if 'account_analytic_id' in line:
                line['account_analytic_id'] = line.get('account_analytic_id', False) and line['account_analytic_id'][0]
            if 'tax_code_id' in line :
                if isinstance(line['tax_code_id'],tuple) and len(line['tax_code_id']) >0 :
                    line['tax_code_id'] = line['tax_code_id'][0]
            if 'base_code_id' in line :
                if isinstance(line['base_code_id'],tuple) and len(line['base_code_id']) >0 :
                    line['base_code_id'] = line['base_code_id'][0]
        return map(lambda x: (0,0,x), lines)