Hi,

You can create section programatically by using the following code                

class SaleOrder(models.Model):
    _inherit = 'sale.order'

    def custom_function(self):
        order_lines = []
        val = (0, 0, {
            'display_type': 'line_section',
            'name': 'SECTION NAME',
        })
        order_lines.append(val)
        self.update({'order_line': order_lines})