How To Find : If two different date ranges intersects

I was making a Odoo module today, it had a requirement to find the products that has offering within two ranges. Each of the product has different range for discounts/offers. It is sort of like the following:

For example, a shampoo discount starts from 01-06-2020 and ends at 20-06-2020, while another product like a soap discount starts from 10-06-2020 and ends at 22-06-2020. Now if I look for discounted credit notes to apply within a range, then we need to provide some time range, that these ranges intersect. For example, if I want to find discounts that were given within 02-06-2020 – 11 – 06 – 2020, then we should get both the discounts available here, as the discounts were still available for a day to the Soap and a few days for Shampoo. That means, we need to find if any of the given two ranges intersects with the ranges we have discounts for.

The easiest way to calculate this, is to check which date is max among the lower boundaries and which date is minimum in the lower boundaries. This should follow that the starting date would be less than or equal to the ending date, but never greater than the ending date. If greater than, then it does not intersect logically. In python, we can do this like the following:

# first we find all the vendor discounts, it has property start_date and end_date
vendor_discounts = self.env[''].search([])

# list to keep the vendor discount instances
vendor_discount_id_in_range = []

# from the form, we get date_from and date_to, where the dates intersect
for vendor_discount in vendor_discounts:
   # here is the logic to find intersects
    if max(self.date_from, vendor_discount.start_date) <= min(self.date_to, vendor_discount.end_date):

So, the logic going to be like the following:

if max(input_date_from, start_date_to_match) <= min(input_date_to, end_date_to_match)

How to Install Odoo 13 in CentOS 7

Odoo is currently one of the most popular tool for business purposes. It has a community edition, that allows managing ERP at very low cost. Odoo was previously known as OpenERP. Odoo requires to be installed on a dedicated server or VPS. Odoo 13 had come out on October, 2019. Odoo 14 hasn’t been released yet for production. I will have a straight forward how to on installing the latest Odoo 13 in CentOS 7.

Log in to your system and update

First step would be to login to your system and then update the system using yum.

ssh [email protected]_ip

You may check the CentOS version from the redhat release file using the following:

cat /etc/redhat-release

It should show you something like the following if you

CentOS Linux release 7.8.2003 (Core)

Now, you may try updating the system with yum

yum update -y

Once done, now install the EPEL repository as we need it to satisfy a couple of dependecies:

yum install epel-release

Install Python 3.6 packages and Odoo dependencies

We need Python 3.6 at least to run Odoo 13. Odoo 12 had support for Python 3.5, unfortunately, Odoo 13 doesn’t. We will use ‘Software Collection (scl)’ repository to install and use Python 3.6. To find the available Python versions in SCL, you may check the following:

SCL Repository for Python

Now, to install Python 3.6 using SCL, we first need to install the SCL repository for Centos:

yum install centos-release-scl

Once the SCL is loaded, now, you may install the python 3.6 using the following command:

yum install rh-python36

Once the Python is installed, now we will install several tools and packages for Odoo dependencies with the following command:

yum install git gcc nano wget nodejs-less libxslt-devel bzip2-devel openldap-devel libjpeg-devel freetype-devel

Create Odoo User

We now need to create a system user and group for Odoo and define a home directory to /opt/odoo

useradd -m -U -r -d  /opt/odoo -s /bin/bash odoo

You may use any username here, but remember to create the same username for the PostgreSQL as well.

Install PostgreSQL

CentOS base repository unfortunately, comes with Postgresql 9.2. But we want to use PostgreSQL 9.6 for our Odoo installation. You may check the available PostgreSQL for CentOS 7 using the following command:

yum list postgresql*

As by default CentOS 7 does not provide the PostgreSQL 9.6, we would use PostgreSQL official repository to download and install the 9.6 version.

First, we install the Postgres Yum Repository using the following command:

yum install

Now, you may install PostgreSQL 9.6 and related required packages using the following command:

yum install postgresql96 postgresql96-server postgresql96-contrib postgresql96-libs

Now, we need to initialize the postgres database and start it. You may do that using the following:

# Initialize the DB
/usr/pgsql-9.6/bin/postgresql96-setup initdb

# Start the database
systemctl start postgresql-9.6.service

Now you may enable Postgres to start when booting up using the systemctl enable command:

systemctl enable postgresql-9.6.service

Now, we need to create a database user for our Odoo installation. You may do that using the following:

su - postgres -c "createuser -s odoo"

Note: If you have created a different user for Odoo installation other than ‘odoo’ than you should change the username here as well.

Install Wkhtmltopdf

Wkhtmltopdf is a open source tool to make html in pdf format so that you may print pdf reports. This tool is used by Odoo and requires to be installed as dependency. CentOS 7 repository does not provide the latest version of this tool, and Odoo requires you to use the latest version. Hence, we require to download the latest version from the Wkhtmltopdf website and install it. To do that, you may first visit the page:

The page gives you the direct rpm download link for each version of CentOS/Ubuntu/Mac etc. Download the stable version for CentOS 7. At the time of writing, the URL for CentOS 7 x86_64 bit is the following:

You may install this using the following:

cd /opt/
yum localinstall wkhtmltox-0.12.6-1.centos7.x86_64.rpm

Install and Configure Odoo 13

If you have come all through here, that means you are done with the all dependency installations before starting to download Odoo 13 source code. We will download Odoo 13 from it’s Github repo and use virtualenv to create an isolated python environment to install this python software.

First, login as odoo from root:

su - odoo

Clone the Odoo source code from Github repository:

git clone --depth 1 --branch 13.0 /opt/odoo/odoo13

This will bring the Odoo 13 branch from the Odoo repository and put it inside the folder /opt/odoo/odoo13

Now, we need to enable software collections in order to access python binaries:

scl enable rh-python36 bash

Then we need to create a virtual environment to complete the installation:

cd /opt/odoo
python3 -m venv odoo13-venv

Now, you may activate the virtual environment you have just created:

source odoo13-venv/bin/activate

Now, we upgrade the pip and install the wheel library:

pip install --upgrade pip
pip3 install wheel

Once done, now we can using pip3 to install all the required Python modules from the requirements.txt file:

pip3 install -r odoo13/requirements.txt

Once the installation is complete, now we can deactivate the virtual environment and get back to the root user

deactivate && exit ; exit

If you think, you will create custom modules, you may now create it and give odoo the permission accordingly:

mkdir /opt/odoo/odoo13-custom-addons
chown odoo: /opt/odoo/odoo13-custom-addons

Now, we can fill up the odoo configuration file. First open the odoo.conf file:

nano /etc/odoo.conf

You may paste the following inside:

; This is the password that allows database operations:
admin_passwd = set_the_password_to_create_odoo_database
db_host = False
db_port = False
db_user = odoo
db_password = False
addons_path = /opt/odoo/odoo13/addons,/opt/odoo/odoo13-custom-addons
; You can enable log file with uncommenting the next line
; logfile = /var/log/odoo13/odoo.log

Please do not forget to change the password ‘set_the_password_to_create_odoo_database’ with a new strong password. This would be used to create Odoo databases from the login screen.

Create the systemd service file and start Odoo 13

Now, we will create a service file, to be able to start, stop and restart Odoo daemon. To do that, first create a service file using the following:

nano /etc/systemd/system/odoo13.service

and paste the following:

Requires=postgresql-9.6.service postgresql-9.6.service

ExecStart=/usr/bin/scl enable rh-python35 -- /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.conf


Now, save the file and exit.

Now, you need to reload the systemd daemon to be able to read the latest changes you have made to services. To do that, run:

systemctl daemon-reload

Finally, now we can start Odoo 13 instance using the following command:

systemctl start odoo13

If you are interested to check the status of the instance, you may do this:

systemctl status odoo13
[[email protected] ~]# systemctl status odoo13
● odoo13.service - Odoo13
   Loaded: loaded (/etc/systemd/system/odoo13.service; enabled; vendor preset: disabled)
   Active: active (running) since Sun 2020-09-13 08:26:46 EDT; 23h ago
 Main PID: 24502 (scl)
   CGroup: /system.slice/odoo13.service
           ├─24502 /usr/bin/scl enable rh-python36 -- /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.conf
           ├─24503 /bin/bash /var/tmp/sclSWH04z
           └─24507 /opt/odoo/odoo13-venv/bin/python3 /opt/odoo/odoo13/odoo-bin -c /etc/odoo.conf

It show green active running, if everything worked out. If you see no error, you may now enable Odoo to start during the boot:

systemctl enable odoo13

If you would like to see the logs, you may either use the journal tools like the following:

journalctl -u odoo13

or uncomment the following line to log the debugs in /etc/odoo.conf

logfile = /var/log/odoo13/odoo.log

After making any change to /etc/odoo.conf, do not forget the restart the Odoo13 instance using systemctl.

Test the Installation

You may now test the installation using http://your_server_ip:8069. If everything worked, it should come up. If it doesn’t, you may try stopping your ‘firewalld’ to see if firewall is blocking the port or not:

systemctl stop firewalld

At Mellowhost, we provide Odoo installation and configuration assistance for absolute free of charge. If you are willing to try out any of our VPS for Odoo, you may do so and talk with us through the Live chat or the ticket for Odoo assistance.

Furthermore, Good luck.

How to get the string/part/word/text within brackets in Python using Regex


For example, you have a string like the following:

[lagril] L.A. Girl Pro. Setting HD Matte Finish Spray

While you are scanning the line, you would like to extract the following word from it ‘lagril’, which you are interested in. How to do that?


Our problem falls into a common string extraction problem we face in software engineering. We usually do this using Regular Expressions. Let’s build the regular expression logic first, using

We need to find a string that starts with ‘[‘ bracket and ends with ‘]’ bracket, and in the middle, we expect alphanumeric word with small or capital letters, and they can be anything from 0 to any. So, this should be as simple as the following:


Now, this should help us target the words that comes within bracket in a sentence/large string. But the trick to grab the text within the bracket is to group them. To use group in regex, we use () brackets without back slash in front. So if the regex is as following:


This will put the matching string in group 1. Now, how can you get what is in the group 1 of a regular expression engine? Let’s dive into python now:

# let's import regular expression engine first
import re

# our string
txt = '[lagril] L.A. Girl Pro. Setting HD Matte Finish Spray'

# our regex search would be as following:
x ="\[([A-Za-z0-9]*)\]", txt)

# we know this will put the inner text in group 1. regex object that returned by, has a method called 'group()' to catch the groups matches regex. You may use the following # prints lagril

Odoo Controller JSON Route Returns 404 – werkzeug.exceptions.NotFound

Even though, if you have defined your routes properly, you are seeing an error of the following:

    "id": null,
    "jsonrpc": "2.0",
    "error": {
        "http_status": 404,
        "code": 404,
        "data": {
            "name": "werkzeug.exceptions.NotFound",
            "debug": "Traceback (most recent call last):\n  File \"/opt/odoo/odoo12/odoo/\", line 656, in _handle_exception\n    return super(JsonRequest, self)._handle_exception(exception)\n  File \"/opt/odoo/odoo12/odoo/\", line 314, in _handle_exception\n    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])\n  File \"/opt/odoo/odoo12/odoo/tools/\", line 87, in reraise\n    raise value\n  File \"/opt/odoo/odoo12/odoo/\", line 1460, in _dispatch_nodb\n    func, arguments = self.nodb_routing_map.bind_to_environ(request.httprequest.environ).match()\n  File \"/opt/odoo/odoo12-venv/lib64/python3.5/site-packages/werkzeug/\", line 1563, in match\n    raise NotFound()\nwerkzeug.exceptions.NotFound: 404: Not Found\n",
            "message": "404: Not Found",
            "exception_type": "internal_error",
            "arguments": []
        "message": "404: Not Found"

This error doesn’t return when you use the http.route as type ‘http’ or default, which is still http, but returns when you use the type ‘json’. One of the cause why the error return is that, you have multiple Odoo databases and Odoo is failing to detect the usable database for the type json. For the type, http, Odoo usually can predict what to use, while for the type json, it can not. For such cases, you would need to use the ‘db-filter’ to add the default database to load for Odoo on the odoo-bin command. If you are using the systemd service file, append the line with the following:


where ‘my_prod’ is your database name.

So the service ExecStart would look like the following:

ExecStart=/usr/bin/scl enable rh-python35 -- /opt/odoo/odoo12-venv/bin/python3 /opt/odoo/odoo12/odoo-bin -c /etc/odoo.conf --limit-time-real 1009999999 --limit-time-cpu 1009999999 --limit-memory-hard 89179869184000000 --limit-memory-soft 57179869184000000 --db-filter=^my_prod$

After making the change, reload your systemctl and restart your odoo-bin:

systemctl daemon-reload
service odoo12 restart

This should do the job.

Dirty Odoo Hacks: How to Know If a Scheduled Action is Running

This blog post goes to my ‘Dirty Hack’ series, where I try to open the gross hacking attempts I practically use in several of my projects.

Odoo is my favorite piece of framework. Even though it has evolved as OpenERP, but the extend ability that Odoo gives, probably can take it anywhere, any other framework unable to, without massive change to their base architecture. This goes to the pros of Odoo, while the biggest cons of Odoo, is that it is not owned/developed by a major ‘English’ speaking company/people. If you go through the Odoo documentation, you can clearly understand the difference I am talking about. One key reason, Odoo is not often seen everywhere, probably because of poor documentation. Most of the things are not explained in details, as Odoo is a large piece of software, makes it difficult for developers to dig it down and extend.

Odoo has it’s own scheduling system, which they call ‘Scheduled Actions’. Odoo manages a model ‘ir.cron’ to manage the Scheduled Actions. If you look at the model details from (on debug mode)
Odoo >> Settings >> Technical >> Database Structure >> Model
you will see, there is no field it uses to detect if the scheduled action is running or stopped. It has a ‘state’ property though, which does not mean the status like many other odoo models. Here is a output of state property from Odoo shell:

>>> cron_id = self.env['ir.cron'].browse(18)
>>> cron_id.state


That says, it is telling you what kind of operation it is going to execute, here it is saying, this scheduled action is executing a ‘Python Code’ here.

There are times, when you might require to determine whether the scheduled action is running or not. In my case, it was to track down the some syncing issues, like to find out whether the syncing is doing it’s job properly through some custom methods. As Odoo doesn’t provide a way to do this, I had to find a dirty way to do it. Here is how I did it.

Odoo runs in Postgres SQL, which is basically an open source version of Oracle like Object Oriented Database system. Like many other OODS, Postgres also provide an operation called the following:


From the oracle documentation, it means:

Oracle provides the FOR UPDATE NOWAIT clause in SQL syntax to allow the developer to lock a set of Oracle rows for the duration of a transaction.

When the scheduled action runs, it locks the specific row of the ir_cron table, of course it would because it has to update that specific row with nextcall and other field data. So if a cron is running, and you try to put a lock with another process, will basically fail, which means the cron is running, otherwise the opposite is true. Viola, that should work for us, isn’t it? Simple! Then again, you have to remember, the lock will put in place for the amount of time you specify, or you have to throw an early rollback (why not a commit? to be in safety to avoid any unwanted data being committed to the database during that session). Here is the simple method to do the whole process:

def _check_if_cron_running(self):
cron_id = self.env['ir.cron'].browse(18)
""" assuming the cron id is 18, you can do any kind of search, like searching by name of the scheduled action etc """
if cron_id:
self._cr.execute("""SELECT id FROM "%s" WHERE id IN %%s FOR UPDATE NOWAIT""" % cron_id._table, [tuple(cron_id.ids)], log_exceptions=False)
""" self._cr.execute is used to execute a direct sql command, each ir.cron model data will have 'ids' to tell you which ids are selected, and _table to tell you what is the table name for the model, here it should return ir_cron """
self._cr.rollback() # we need to rollback and give the database cursor back to the other process ASAP"log and operate whatever here, this section is reached when the scheduled action is stopped or not running")
except psycopg2.OperationalError:
self._cr.rollback() # we need to rollback the errors and give control to the other process"log and operate whatever here, this section is reached when the scheduled action is running")

Remember, this is dirty, you are hitting direct SQL, on a near around 500 model based framework. So, please take care of your things before placing this in production. Rest assured, keep using Odoo for future! A brilliant piece of art is Odoo!

How to Empty a Model In Odoo / Mass Delete in Odoo / Mass Unlink

In Odoo, we use unlink() ORM method to delete a record. But if you are trying to empty a model or wants to delete multiple records, the best way to do it, is to use two steps.

First, search the records:

record_set = self.env['your.model'].search([])

Second, unlink them all at once instead of looping through them:


If you have a list of ids, search them using the list:

ids = [1, 2, 3, 10, 11, 12]
record_set = self.env['your.model'].search([('id', 'in', ids)])

and unlink:


Remember, there is no need to loop through this iterable object, odoo unlink does it for you.

TIPS: If you want to get all the ids in a model directly in a list, you can use the following:

record_list = self.env['your.model'].search([]).ids

How to Hide a Column Dynamically in a Parent Model in Tree View on Odoo

We all know how to hide a column in a model based on parent value matching in Odoo installation. I have already written a post on this here:

How to hide a column ‘dynamically’ in Tree View on Odoo

Above case works when you are trying a hide a column in a sale order line, or move line or invoice line. But what if, you want to hide a column in stock picking delivery tree view or the receipt view? The above method, will not work, because column_invisible only works when the parent is referenced. But in a tree view list like ‘Deliver Orders’ under Inventory Overview, if you want to hide a column based on condition, how do we do that?

The answer is, we use data from context and set the attribute ‘invisible’ to True based on the context value. We can either do that by using any existing context value or we can add a context value using a computed field property and match it in the xml.

I will discuss on how can we use the existing context key:value pair in hiding a column on stock.picking model.

First, let’s imagine, we have a character field on stock.picking called ‘woocommerce_id’.

class stock_picking(models.Model):
_inhert = 'stock.picking'

woocommerce_id = fields.Char(string="Woocommerce ID")

Now the xml for Inventory overview stock.picking trees would be inheriting stock.vpicktree

<record id="inherit_delivery_picking" model="ir.ui.view">
<field name="name"></field>
<field name="model">stock.picking</field>
<field name="inherit_id" ref="stock.vpicktree"/>
<field name="arch" type="xml">
<xpath expr="//field[@name='location_dest_id']" position="after">
<field name="woocommerce_id"/>

Now, the above will show woocommerce_id in all vpicktree view, like ‘Delivery Orders’, ‘Receipts’, ‘Internal Transfers’. But What if, you want to show this field to only Delivery Orders?

To do that, we need to know the value for ‘default_picking_type_id’. This value is automatically set on stock.picking model view in the context by Odoo (Hints: You may view all the keys available to context in a model, by creating a computed field, that writes self.env.context.keys() to a file or show it in the tree view to find the keys, and self.env.context.get(‘key_name’) to find the value for it).

If you check the different values set by that key for different pages, you can see, it is set to 1 for delivery orders, 3 for receipts and 5 for internal transfers. Now if you want to show the woocommerce_id field to only delivery receipts, we set the attribute invisible for that field when the context key value is not 1 like following:

<field name="woocommerce_id" invisible="context.get('default_picking_type_id') != 1"/>

Save it, upgrade the module, and see the magic! cheers!

How to Update Context in Odoo

You may want to pass some data to a specific page in Odoo, and change the fields based on those data. In those cases, you want to use Context. Context is a data structure passed to the request object that contains hidden values, and can be used to change results of the page.

Context is a frozendict data type in Odoo. That’s why you can change it like you do in a dict data type, for example:

'test': 'test_value',

As the Context is frozendict, it won’t take such changes. Odoo provides a way to change values, it’s called ‘with_context’. The syntax is as following:

self = self.with_context({
'test': 'test_value',

This one should rewrite the context available in the self object by adding the new key:value pair you have mentioned. There are times, this might not work as expected, and you want a patch technique to update the context. This can be done by changing the data type to dict.

self.env.context = dict(self.env.context)
'test': 'test_value',

This would also add the new key:value pair to your context and work as expected. There is almost no security concern here for converting the frozendict as the context will destroy once the page is left soon enough.

How to Validate Odoo Invoice Automatically

You might want to validate your odoo invoices automatically, without bothering your users to go to each vendor/customer bill and validate them, instead triggering based on certain conditions. It’s a 4 step code:

First, we get the invoice:

invoice_id = self.env['account.invoice'].browse(your_invoice_id)

Assign the date to it:


Create the invoice moves:


Now you can validate the invoice:


How to Add Invoice to Purchase Order in Odoo Automatically

I was facing an issue in two way matching algorithm for Incoming Receipts & Vendor bills in my Odoo installation. As vendor bills are tagged in Purchase Orders only through use of ‘Create Bill’, I had to make an algorithm to calculate the matching. Remember, the match would only work if the supply chain members follows the right way of doing it, otherwise, it would fail. That’s what happened, it fails almost 3 times out of 10. Then I realized, the invoice needs to be pinned automatically in the stock.picking model, instead of purchase.order model at the time a Receipt is validated, to keep the tracking for my matching.

While doing so, first challenge is to pin an invoice to a purchase id. By default, the model for invoicing, ‘account.invoice’ has a foreign read only key for purchase, which is purchase_id. But remember, this is a read only field, and can’t be written/created in a new or existing record using record. I dig down the Odoo codes a little under purchase/models/ and could find the Odoo function that can do the job for us. It’s called ‘purchase_order_change()’.

Here is a snippet of adding an invoice automatically to a purchase ID:

invoice_id = self.env['account.invoice'].create({
'type': 'in_invoice',


This will create an invoice in Draft state. Remember, you need to validate this invoice, if you would like to create the invoice number, not just an invoice entry. You may do it manually or you may do it automatically ‘How to Automatically Validate an Invoice in Odoo

Remember, I am triggering the snippet from the stock.picking, not from purchase.order, which is why, the ‘self’, is related to stock.picking and calling self.purchase_id to link the original purchase_id that triggered the stock.picking record.

Now, a small tip. What if, if you want to align the invoice to only have the products you have received in this particular receipt? Easy as pie:

for invoice_line in invoice_id.mapped('invoice_line_ids'):
check = 1
for move_line in self.mapped('move_line_ids'):
if ==
check = 0

if check:

Simple! Isn’t it? Happy coding!