An example of XLSX report for partners on a module called
\`module_name\`:

A python class :

    from odoo import models

    class PartnerXlsx(models.AbstractModel):
        _name = 'report.module_name.report_name'
        _inherit = 'report.report_xlsx.abstract'

        def generate_xlsx_report(self, workbook, data, partners):
            for obj in partners:
                report_name = obj.name
                # One sheet by partner
                sheet = workbook.add_worksheet(report_name[:31])
                bold = workbook.add_format({'bold': True})
                sheet.write(0, 0, obj.name, bold)

To manipulate the `workbook` and `sheet` objects, refer to the
[documentation](http://xlsxwriter.readthedocs.org/) of `xlsxwriter`.

A report XML record :

    <record id="action_report_partner_xlsx" model="ir.actions.report">
        <field name="name">Print to XLSX</field>
        <field name="model">res.partner</field>
        <field name="report_type">xlsx</field>
        <field name="report_name">module_name.report_name</field>
        <field name="report_file">module_name.report_file</field>
        <field name="binding_model_id" ref="res.partner"/>
        <field name="binding_type">report</field>
        <field name="attachment_use" eval="False"/>
    </record>