diff --git a/contract_variable_quantity/__manifest__.py b/contract_variable_quantity/__manifest__.py
index 2c0a42e52..e5c8ea88a 100644
--- a/contract_variable_quantity/__manifest__.py
+++ b/contract_variable_quantity/__manifest__.py
@@ -4,21 +4,20 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
 {
-    'name': 'Variable quantity in contract recurrent invoicing',
-    'version': '12.0.3.0.0',
-    'category': 'Contract Management',
-    'license': 'AGPL-3',
-    'author': "Tecnativa,"
-              "Odoo Community Association (OCA)",
-    'website': 'https://www.tecnativa.com',
-    'depends': ['contract'],
-    'data': [
-        'security/ir.model.access.csv',
-        'views/abstract_contract_line.xml',
-        'views/contract_line_formula.xml',
-        'views/contract_line_views.xml',
-        'views/contract_template.xml',
-        'views/contract.xml',
+    "name": "Variable quantity in contract recurrent invoicing",
+    "version": "12.0.3.0.0",
+    "category": "Contract Management",
+    "license": "AGPL-3",
+    "author": "Tecnativa," "Odoo Community Association (OCA)",
+    "website": "https://www.tecnativa.com",
+    "depends": ["contract"],
+    "data": [
+        "security/ir.model.access.csv",
+        "views/abstract_contract_line.xml",
+        "views/contract_line_formula.xml",
+        "views/contract_line_views.xml",
+        "views/contract_template.xml",
+        "views/contract.xml",
     ],
-    'installable': True,
+    "installable": True,
 }
diff --git a/contract_variable_quantity/migrations/12.0.2.0.0/pre-migration.py b/contract_variable_quantity/migrations/12.0.2.0.0/pre-migration.py
index 696654698..78533de77 100644
--- a/contract_variable_quantity/migrations/12.0.2.0.0/pre-migration.py
+++ b/contract_variable_quantity/migrations/12.0.2.0.0/pre-migration.py
@@ -10,23 +10,41 @@ _logger = logging.getLogger(__name__)
 
 def migrate(cr, version):
     xmlids_to_rename = [
-        ('contract_sale.account_analytic_account_own_salesman',
-         'contract_sale.contract_contract_own_salesman'),
-        ('contract_sale.account_analytic_account_see_all',
-         'contract_sale.contract_contract_see_all'),
-        ('contract_sale.account_analytic_contract_salesman',
-         'contract_sale.contract_template_salesman'),
-        ('contract_sale.account_analytic_contract_sale_manager',
-         'contract_sale.contract_template_sale_manager'),
-        ('contract_sale.account_analytic_invoice_line_saleman',
-         'contract_sale.contract_line_saleman'),
-        ('contract_sale.account_analytic_invoice_line_manager',
-         'contract_sale.contract_line_manager'),
-        ('contract_sale.account_analytic_contract_line_salesman',
-         'contract_sale.contract_template_line_salesman'),
-        ('contract_sale.account_analytic_contract_line_manager',
-         'contract_sale.contract_template_line_manager'),
-        ('contract_sale.account_analytic_account_contract_salesman',
-         'contract_sale.contract_contract_salesman'),
+        (
+            "contract_sale.account_analytic_account_own_salesman",
+            "contract_sale.contract_contract_own_salesman",
+        ),
+        (
+            "contract_sale.account_analytic_account_see_all",
+            "contract_sale.contract_contract_see_all",
+        ),
+        (
+            "contract_sale.account_analytic_contract_salesman",
+            "contract_sale.contract_template_salesman",
+        ),
+        (
+            "contract_sale.account_analytic_contract_sale_manager",
+            "contract_sale.contract_template_sale_manager",
+        ),
+        (
+            "contract_sale.account_analytic_invoice_line_saleman",
+            "contract_sale.contract_line_saleman",
+        ),
+        (
+            "contract_sale.account_analytic_invoice_line_manager",
+            "contract_sale.contract_line_manager",
+        ),
+        (
+            "contract_sale.account_analytic_contract_line_salesman",
+            "contract_sale.contract_template_line_salesman",
+        ),
+        (
+            "contract_sale.account_analytic_contract_line_manager",
+            "contract_sale.contract_template_line_manager",
+        ),
+        (
+            "contract_sale.account_analytic_account_contract_salesman",
+            "contract_sale.contract_contract_salesman",
+        ),
     ]
     openupgrade.rename_xmlids(cr, xmlids_to_rename)
diff --git a/contract_variable_quantity/models/abstract_contract_line.py b/contract_variable_quantity/models/abstract_contract_line.py
index 07c4ec128..9d9dfa91b 100644
--- a/contract_variable_quantity/models/abstract_contract_line.py
+++ b/contract_variable_quantity/models/abstract_contract_line.py
@@ -7,15 +7,12 @@ from odoo import fields, models
 
 
 class ContractAbstractContractLine(models.AbstractModel):
-    _inherit = 'contract.abstract.contract.line'
+    _inherit = "contract.abstract.contract.line"
 
     qty_type = fields.Selection(
-        selection=[
-            ('fixed', 'Fixed quantity'),
-            ('variable', 'Variable quantity'),
-        ],
+        selection=[("fixed", "Fixed quantity"), ("variable", "Variable quantity")],
         required=True,
-        default='fixed',
+        default="fixed",
         string="Qty. type",
     )
     qty_formula_id = fields.Many2one(
diff --git a/contract_variable_quantity/models/contract.py b/contract_variable_quantity/models/contract.py
index b0f6755b6..c6be92da2 100644
--- a/contract_variable_quantity/models/contract.py
+++ b/contract_variable_quantity/models/contract.py
@@ -10,6 +10,6 @@ class ContractContract(models.Model):
     _inherit = "contract.contract"
 
     skip_zero_qty = fields.Boolean(
-        string='Skip Zero Qty Lines',
+        string="Skip Zero Qty Lines",
         help="If checked, contract lines with 0 qty don't create invoice line",
     )
diff --git a/contract_variable_quantity/models/contract_line.py b/contract_variable_quantity/models/contract_line.py
index 714e8eb51..683b849d6 100644
--- a/contract_variable_quantity/models/contract_line.py
+++ b/contract_variable_quantity/models/contract_line.py
@@ -9,30 +9,28 @@ from odoo.tools.safe_eval import safe_eval
 
 
 class AccountAnalyticInvoiceLine(models.Model):
-    _inherit = 'contract.line'
+    _inherit = "contract.line"
 
     @api.multi
     def _get_quantity_to_invoice(
         self, period_first_date, period_last_date, invoice_date
     ):
-        quantity = super(
-            AccountAnalyticInvoiceLine, self
-        )._get_quantity_to_invoice(
+        quantity = super(AccountAnalyticInvoiceLine, self)._get_quantity_to_invoice(
             period_first_date, period_last_date, invoice_date
         )
         if not period_first_date or not period_last_date or not invoice_date:
             return quantity
-        if self.qty_type == 'variable':
+        if self.qty_type == "variable":
             eval_context = {
-                'env': self.env,
-                'context': self.env.context,
-                'user': self.env.user,
-                'line': self,
-                'quantity': quantity,
-                'period_first_date': period_first_date,
-                'period_last_date': period_last_date,
-                'invoice_date': invoice_date,
-                'contract': self.contract_id,
+                "env": self.env,
+                "context": self.env.context,
+                "user": self.env.user,
+                "line": self,
+                "quantity": quantity,
+                "period_first_date": period_first_date,
+                "period_last_date": period_last_date,
+                "invoice_date": invoice_date,
+                "contract": self.contract_id,
             }
             safe_eval(
                 self.qty_formula_id.code.strip(),
@@ -40,7 +38,7 @@ class AccountAnalyticInvoiceLine(models.Model):
                 mode="exec",
                 nocopy=True,
             )  # nocopy for returning result
-            quantity = eval_context.get('result', 0)
+            quantity = eval_context.get("result", 0)
         return quantity
 
     @api.multi
@@ -49,13 +47,11 @@ class AccountAnalyticInvoiceLine(models.Model):
             invoice_id=invoice_id, invoice_values=invoice_values,
         )
         if (
-            'quantity' in vals
+            "quantity" in vals
             and self.contract_id.skip_zero_qty
             and float_is_zero(
-                vals['quantity'],
-                self.env['decimal.precision'].precision_get(
-                    'Product Unit of Measure'
-                ),
+                vals["quantity"],
+                self.env["decimal.precision"].precision_get("Product Unit of Measure"),
             )
         ):
             vals = {}
diff --git a/contract_variable_quantity/models/contract_line_formula.py b/contract_variable_quantity/models/contract_line_formula.py
index 3493cb974..2760af000 100644
--- a/contract_variable_quantity/models/contract_line_formula.py
+++ b/contract_variable_quantity/models/contract_line_formula.py
@@ -3,38 +3,36 @@
 # Copyright 2018 ACSONE SA/NV
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import _, api, fields, models, exceptions
+from odoo import _, api, exceptions, fields, models
 from odoo.tools.safe_eval import safe_eval
 
 
 class ContractLineFormula(models.Model):
-    _name = 'contract.line.qty.formula'
-    _description = 'Contract Line Formula'
+    _name = "contract.line.qty.formula"
+    _description = "Contract Line Formula"
 
     name = fields.Char(required=True, translate=True)
     code = fields.Text(required=True, default="result = 0")
 
-    @api.constrains('code')
+    @api.constrains("code")
     def _check_code(self):
         eval_context = {
-            'env': self.env,
-            'context': self.env.context,
-            'user': self.env.user,
-            'line': self.env['contract.line'],
-            'contract': self.env['contract.contract'],
-            'invoice': self.env['account.invoice'],
-            'quantity': 0,
-            'period_first_date': False,
-            'period_last_date': False,
-            'invoice_date': False,
+            "env": self.env,
+            "context": self.env.context,
+            "user": self.env.user,
+            "line": self.env["contract.line"],
+            "contract": self.env["contract.contract"],
+            "invoice": self.env["account.invoice"],
+            "quantity": 0,
+            "period_first_date": False,
+            "period_last_date": False,
+            "invoice_date": False,
         }
         try:
-            safe_eval(
-                self.code.strip(), eval_context, mode="exec", nocopy=True
-            )
+            safe_eval(self.code.strip(), eval_context, mode="exec", nocopy=True)
         except Exception as e:
             raise exceptions.ValidationError(
-                _('Error evaluating code.\nDetails: %s') % e
+                _("Error evaluating code.\nDetails: %s") % e
             )
-        if 'result' not in eval_context:
-            raise exceptions.ValidationError(_('No valid result returned.'))
+        if "result" not in eval_context:
+            raise exceptions.ValidationError(_("No valid result returned."))
diff --git a/contract_variable_quantity/tests/test_contract_variable_quantity.py b/contract_variable_quantity/tests/test_contract_variable_quantity.py
index 3e295a284..d7a829f1d 100644
--- a/contract_variable_quantity/tests/test_contract_variable_quantity.py
+++ b/contract_variable_quantity/tests/test_contract_variable_quantity.py
@@ -12,48 +12,46 @@ from odoo import exceptions
 class TestContractVariableQuantity(odoo.tests.HttpCase):
     def setUp(self):
         super(TestContractVariableQuantity, self).setUp()
-        self.partner = self.env['res.partner'].create({'name': 'Test partner'})
-        self.product = self.env['product.product'].create(
-            {'name': 'Test product'}
-        )
-        self.contract = self.env['contract.contract'].create(
+        self.partner = self.env["res.partner"].create({"name": "Test partner"})
+        self.product = self.env["product.product"].create({"name": "Test product"})
+        self.contract = self.env["contract.contract"].create(
             {
-                'name': 'Test Contract',
-                'partner_id': self.partner.id,
-                'pricelist_id': self.partner.property_product_pricelist.id,
+                "name": "Test Contract",
+                "partner_id": self.partner.id,
+                "pricelist_id": self.partner.property_product_pricelist.id,
             }
         )
-        self.formula = self.env['contract.line.qty.formula'].create(
+        self.formula = self.env["contract.line.qty.formula"].create(
             {
-                'name': 'Test formula',
+                "name": "Test formula",
                 # For testing each of the possible variables
-                'code': 'env["res.users"]\n'
+                "code": 'env["res.users"]\n'
                 'context.get("lang")\n'
-                'user.id\n'
-                'line.qty_type\n'
-                'contract.id\n'
-                'quantity\n'
-                'period_first_date\n'
-                'period_last_date\n'
-                'invoice_date\n'
-                'result = 12',
+                "user.id\n"
+                "line.qty_type\n"
+                "contract.id\n"
+                "quantity\n"
+                "period_first_date\n"
+                "period_last_date\n"
+                "invoice_date\n"
+                "result = 12",
             }
         )
-        self.contract_line = self.env['contract.line'].create(
+        self.contract_line = self.env["contract.line"].create(
             {
-                'contract_id': self.contract.id,
-                'product_id': self.product.id,
-                'name': 'Test',
-                'qty_type': 'variable',
-                'qty_formula_id': self.formula.id,
-                'quantity': 1,
-                'uom_id': self.product.uom_id.id,
-                'price_unit': 100,
-                'discount': 50,
-                'recurring_rule_type': 'monthly',
-                'recurring_interval': 1,
-                'date_start': '2016-02-15',
-                'recurring_next_date': '2016-02-29',
+                "contract_id": self.contract.id,
+                "product_id": self.product.id,
+                "name": "Test",
+                "qty_type": "variable",
+                "qty_formula_id": self.formula.id,
+                "quantity": 1,
+                "uom_id": self.product.uom_id.id,
+                "price_unit": 100,
+                "discount": 50,
+                "recurring_rule_type": "monthly",
+                "recurring_interval": 1,
+                "date_start": "2016-02-15",
+                "recurring_next_date": "2016-02-29",
             }
         )
 
@@ -71,7 +69,7 @@ class TestContractVariableQuantity(odoo.tests.HttpCase):
         self.assertEqual(invoice.invoice_line_ids[0].quantity, 12)
 
     def test_check_skip_zero_qty(self):
-        self.formula.code = 'result=0'
+        self.formula.code = "result=0"
         self.contract.skip_zero_qty = True
         invoice = self.contract.recurring_create_invoice()
         self.assertFalse(invoice.invoice_line_ids)
diff --git a/contract_variable_quantity/views/abstract_contract_line.xml b/contract_variable_quantity/views/abstract_contract_line.xml
index 8a5f2a88e..b6cd8af1d 100644
--- a/contract_variable_quantity/views/abstract_contract_line.xml
+++ b/contract_variable_quantity/views/abstract_contract_line.xml
@@ -1,18 +1,20 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <odoo>
-
-    <record id="contract_abstract_contract_line_form_view"
-            model="ir.ui.view">
+    <record id="contract_abstract_contract_line_form_view" model="ir.ui.view">
         <field name="name">Abstract Contract Line Form View</field>
         <field name="model">contract.abstract.contract.line</field>
-        <field name="inherit_id" ref="contract.contract_abstract_contract_line_form_view"/>
+        <field
+            name="inherit_id"
+            ref="contract.contract_abstract_contract_line_form_view"
+        />
         <field name="arch" type="xml">
             <xpath expr="//label[@for='quantity']" position="before">
-                <field name="qty_type"/>
+                <field name="qty_type" />
             </xpath>
             <xpath expr="//field[@name='quantity']" position="after">
-                <field name="qty_formula_id"
-                       attrs="{'required': [('qty_type', '=', 'variable')], 'invisible': [('qty_type', '!=', 'variable')]}"
+                <field
+                    name="qty_formula_id"
+                    attrs="{'required': [('qty_type', '=', 'variable')], 'invisible': [('qty_type', '!=', 'variable')]}"
                 />
             </xpath>
             <xpath expr="//field[@name='quantity']" position="attributes">
@@ -22,5 +24,4 @@
             </xpath>
         </field>
     </record>
-
 </odoo>
diff --git a/contract_variable_quantity/views/contract.xml b/contract_variable_quantity/views/contract.xml
index 5d6330a99..bf1be85d2 100644
--- a/contract_variable_quantity/views/contract.xml
+++ b/contract_variable_quantity/views/contract.xml
@@ -1,24 +1,30 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <odoo>
-
     <record id="contract_contract_form_view" model="ir.ui.view">
         <field name="model">contract.contract</field>
-        <field name="inherit_id" ref="contract.contract_contract_form_view"/>
+        <field name="inherit_id" ref="contract.contract_contract_form_view" />
         <field name="arch" type="xml">
             <xpath expr="//field[@name='code']" position="after">
-                <field name="skip_zero_qty"/>
+                <field name="skip_zero_qty" />
             </xpath>
-            <xpath expr="//field[@name='contract_line_ids']/tree/field[@name='quantity']" position="before">
-                <field name="qty_type"/>
+            <xpath
+                expr="//field[@name='contract_line_ids']/tree/field[@name='quantity']"
+                position="before"
+            >
+                <field name="qty_type" />
                 <field
                     name="qty_formula_id"
                     attrs="{'invisible': [('qty_type', '!=', 'variable')]}"
                 />
             </xpath>
-            <xpath expr="//field[@name='contract_line_ids']/tree/field[@name='quantity']" position="attributes">
-                <attribute name="attrs">{'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
+            <xpath
+                expr="//field[@name='contract_line_ids']/tree/field[@name='quantity']"
+                position="attributes"
+            >
+                <attribute
+                    name="attrs"
+                >{'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
             </xpath>
         </field>
     </record>
-
 </odoo>
diff --git a/contract_variable_quantity/views/contract_line_formula.xml b/contract_variable_quantity/views/contract_line_formula.xml
index 97791d0f7..b1dec49ef 100644
--- a/contract_variable_quantity/views/contract_line_formula.xml
+++ b/contract_variable_quantity/views/contract_line_formula.xml
@@ -1,15 +1,13 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <odoo>
-
     <record id="view_contract_line_qty_formula_tree" model="ir.ui.view">
         <field name="model">contract.line.qty.formula</field>
         <field name="arch" type="xml">
             <tree>
-                <field name="name"/>
+                <field name="name" />
             </tree>
         </field>
     </record>
-
     <record id="view_contract_line_qty_formula_form" model="ir.ui.view">
         <field name="model">contract.line.qty.formula</field>
         <field name="arch" type="xml">
@@ -17,13 +15,17 @@
                 <sheet>
                     <div class="oe_title">
                         <h1>
-                            <field name="name" placeholder="Name"/>
+                            <field name="name" placeholder="Name" />
                         </h1>
                     </div>
                     <group string="Code">
                         <div style="margin-top: 4px;">
-                            <field name="code" nolabel="1" widget="ace"
-                                   options="{'mode': 'python'}"/>
+                            <field
+                                name="code"
+                                nolabel="1"
+                                widget="ace"
+                                options="{'mode': 'python'}"
+                            />
                             <h3>Help with Python expressions.</h3>
                             <p>You have to insert valid Python code block that
                                 stores at some moment a float/integer value of
@@ -65,9 +67,7 @@
             </form>
         </field>
     </record>
-
-    <record id="action_contract_quantity_formula"
-            model="ir.actions.act_window">
+    <record id="action_contract_quantity_formula" model="ir.actions.act_window">
         <field name="name">Formulas (quantity)</field>
         <field name="res_model">contract.line.qty.formula</field>
         <field name="view_type">form</field>
@@ -78,10 +78,9 @@
             </p>
         </field>
     </record>
-
-    <menuitem id="menu_contract_quantity_formula"
-              action="action_contract_quantity_formula"
-              parent="contract.menu_config_contract"
+    <menuitem
+        id="menu_contract_quantity_formula"
+        action="action_contract_quantity_formula"
+        parent="contract.menu_config_contract"
     />
-
 </odoo>
diff --git a/contract_variable_quantity/views/contract_line_views.xml b/contract_variable_quantity/views/contract_line_views.xml
index f74106298..1d6d3ec90 100644
--- a/contract_variable_quantity/views/contract_line_views.xml
+++ b/contract_variable_quantity/views/contract_line_views.xml
@@ -1,24 +1,26 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <!-- Copyright 2019 Tecnativa - Pedro M. Baeza
      License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). -->
 <odoo>
-
     <record id="contract_line_tree_view" model="ir.ui.view">
-        <field name="name">contract.line tree view (in contract) - Add variable qty fields</field>
+        <field
+            name="name"
+        >contract.line tree view (in contract) - Add variable qty fields</field>
         <field name="model">contract.line</field>
-        <field name="inherit_id" ref="contract.contract_line_tree_view"/>
+        <field name="inherit_id" ref="contract.contract_line_tree_view" />
         <field name="arch" type="xml">
             <field name="quantity" position="before">
-                <field name="qty_type"/>
+                <field name="qty_type" />
                 <field
                     name="qty_formula_id"
                     attrs="{'invisible': [('qty_type', '!=', 'variable')]}"
                 />
             </field>
             <field name="quantity" position="attributes">
-                <attribute name="attrs">{'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
+                <attribute
+                    name="attrs"
+                >{'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
             </field>
         </field>
     </record>
-
 </odoo>
diff --git a/contract_variable_quantity/views/contract_template.xml b/contract_variable_quantity/views/contract_template.xml
index 3deb0bace..72964a3ef 100644
--- a/contract_variable_quantity/views/contract_template.xml
+++ b/contract_variable_quantity/views/contract_template.xml
@@ -1,23 +1,33 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <odoo>
-
     <record id="contract_template_form_view" model="ir.ui.view">
         <field name="name">Contract Template Variable Qty</field>
         <field name="model">contract.template</field>
-        <field name="inherit_id" ref="contract.contract_template_form_view"/>
+        <field name="inherit_id" ref="contract.contract_template_form_view" />
         <field name="arch" type="xml">
-            <xpath expr="//field[@name='contract_line_ids']//field[@name='quantity']" position="before">
-                <field name="qty_type"/>
+            <xpath
+                expr="//field[@name='contract_line_ids']//field[@name='quantity']"
+                position="before"
+            >
+                <field name="qty_type" />
             </xpath>
-            <xpath expr="//field[@name='contract_line_ids']//field[@name='quantity']" position="after">
-                <field name="qty_formula_id"
-                       attrs="{'required': [('qty_type', '=', 'variable')], 'invisible': [('qty_type', '!=', 'variable')]}"
+            <xpath
+                expr="//field[@name='contract_line_ids']//field[@name='quantity']"
+                position="after"
+            >
+                <field
+                    name="qty_formula_id"
+                    attrs="{'required': [('qty_type', '=', 'variable')], 'invisible': [('qty_type', '!=', 'variable')]}"
                 />
             </xpath>
-            <xpath expr="//field[@name='contract_line_ids']//field[@name='quantity']" position="attributes">
-                <attribute name="attrs">{'required': [('qty_type', '=', 'fixed')], 'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
+            <xpath
+                expr="//field[@name='contract_line_ids']//field[@name='quantity']"
+                position="attributes"
+            >
+                <attribute
+                    name="attrs"
+                >{'required': [('qty_type', '=', 'fixed')], 'invisible': [('qty_type', '!=', 'fixed')]}</attribute>
             </xpath>
         </field>
     </record>
-
 </odoo>