Forem: Uhtred M.

Introduction - Reminder System with Message Templates using Django #1

Uhtred M. — Wed, 25 Oct 2023 23:59:50 +0000

In this set of insights we will be developing a reminder system from scratch with the possibility of modeling or creating template messages. The system will be developed with Python and Django Framework. But you can use the principles applied here with your favorite framework, you just need to have a certain level of experience enough to adapt certain concepts to your framework.

So, what is a reminder system, and what is its use?…

Read the full article on uhtred.dev

How to dynamically serialize model fields in Django REST Framework

Uhtred M. — Fri, 29 Sep 2023 21:42:42 +0000

So, how about a scenario that we define our serializer class to access all fields in the model, but we choose which fields to be serialized when we instantiate the serializer class?

Know more reading the full article here!

Criando imagem de dataURL base64 com Python e Django

Uhtred M. — Sat, 16 Sep 2023 17:03:06 +0000

Olá, acabei de postar um bom artigo em meu site sobre como criar imagens a partir de dataURL base64 com Python e Django.

Acesse o artigo aqui.

Creating Image from dataURL base64 with Python and Django

Uhtred M. — Sat, 16 Sep 2023 17:01:39 +0000

Hi, I just post a nice article on my website about Creating Image from dataURL base64 with Python and Django.

Access the article here.

Como modelar um sistema de seguidores semelhante ao do Twitter e Instagram com Pyhton e Django

Uhtred M. — Mon, 11 Sep 2023 13:25:40 +0000

Olá, publiquei um ótimo artigo em meu site sobre como modelar um sistema de seguidores semelhante ao Twitter ou Instagram.

Acesse o artigo aqui.

Anotações de Tipos em Python - Folha de Dicas (Cheat Sheet)

Uhtred M. — Mon, 11 Sep 2023 13:23:21 +0000

Folha de dicas básicas sobre anotações de tipos em Python. Útil para quem está a começar agora com Python e para consulta rápida para quem já é experiente com Python.

Folha de dicas aqui!

Python Type Hints Cheat Sheet

Uhtred M. — Mon, 11 Sep 2023 13:21:20 +0000

Basic cheat sheet on type annotations in Python. Useful for those who are just starting out with Python and for quick reference for those who are already experienced with Python.

Access cheat sheet here!

How to configure nuxt-i18n and fetch with Nuxt 3 for multilingual APIs

Uhtred M. — Thu, 07 Sep 2023 12:14:05 +0000

Hi, I published a nice article on my website about how to configure nuxt-i18n and fetch with Nuxt 3 for multilingual APIs.

Access the article here.

How to model a following system similar to Twitter and Instagram with Python and Django

Uhtred M. — Thu, 31 Aug 2023 13:29:13 +0000

Hi, I published a nice article on my website about how to model a follower system similar to Twitter or Instagram.

Access the article here.

uhtred.dev Is out now! A business around a freelancer

Uhtred M. — Tue, 22 Aug 2023 22:07:48 +0000

After years, I finally decided to take some time (approximately 2 months) to develop my personal website. It's finally finished (or a good part of it hahah) and available to the world!

I decided to set up a website that presents me as the Product Developer freelancer that I am, someone capable of putting together the ideal on-demand team for the realization of a specific product.

In general, the website will serve to:

Present the success cases that I developed with my team. The cases/portfolio I'm referring to here are not just mockups that lead to a client's website, but details of the project/challenge. Its origin, related people and companies, the problem detected, the solution presented and how we implement it.
Share various insights about business, freelancing, programming, design, finance and other topics that can bring people together. Insights will be written by me and partners. You can be one of those partners too, here's the invitation.
Provide some digital products that can complement other entrepreneurs and freelancers.

There isn't much content yet, but we already have enough to get a sense of what I just described above, so I invite you to explore the website and share your impressions if you wish.

Here are some technical details about the website:

Front-end developed with Nuxt.js 3.
Back-end and Back-office developed with Python and Django (Django Admin is the best!!)
Build, test and delivery automation with Gitlab CI and Google Cloud Build
Every website is on Google Cloud, some featured products are: Cloud SQL, Cloud Run and Cloud Storage

That's it, stay tuned for the next achievements!

Django Cloud Task Queue

Uhtred M. — Fri, 08 Oct 2021 21:15:01 +0000

I’m developing and maintaining a Python package to easily integrate your Django Application with Google Cloud Task.

Some features:

Easily push tasks to Cloud Task using a decorator
Automatically route all tasks from a single endpoint
Ease scheduling with native python datetime
Named task to avoid duplicated
Local development support with Redis Queue

Simple and beautiful task definition

from datetime import timedelta
from django.utils.timezone import now
from cloudtask import (
    CloudTaskRequest,
    task)

@task(queue='default')
def add(request: CloudTaskRequest, a: int = 5, b: int = 4) -> None:
    print(f'Running task with args {a=} and {b=}')
    print(a + b)

# pushing task to queue
add(a=2, b=4).delay()

# executing the task immediately without push to queue
add(a=30)()

# scheduling the task
at = now() + timedelta(days=1)
add(b=15).schedule(at=at)

See the repository and full documentation on my Github page.

Thanks to the project bazaar.

If it was helpful or if you found it interesting, also leave an 🙋🏽‍♂️❤️ in the comments. Thank you, looking forward to the next article. Enjoy and follow my work.

See Here, all my resources.
Learn With Me on Youtube.
Follow Me on Instagram to stay updated.

Thanks,
Stay safe!

Django Signals structured as Event emitter

Uhtred M. — Tue, 28 Sep 2021 14:26:36 +0000

Hi, I don’t know if this is the right title 😆, but I have done some good stuff and I hope that’s could be helpful for you.

While I’m develop the RESTful API for a project (bazaar.ao) that will be available soon, with my team from Ahllia LLC. I have the idea to make this structure (I will show you soon below) for events.

At moment we are developing a monolithic application, but we also want to move for Microservices later, so, with that in mind I decided to keep every monolithic's module (django app) the most independent as possible.

So, to share changes/events within modules I decided to use Django Signals.

The problem

First, I started to create a lot of Signal instances for each event such as:

# in: myproject.user.dispatch

from django.dispatch import Signal

account_created = Signal(['user'])
email_created = Signal(['email'])
phone_created = Signal(['phone'])
# and so on…

And after this, I have imported every single instance on signals file to handle the events.

# in: myproject.user.signals

from django.dispatch import receiver
from myproject.user.dispatch import (
    account_created,
    email_created,
    phone_created
)

@receiver(account_created)
def hdl_account_created(sender, user, **kwargs): pass

@receiver(email_created)
def hdl_email_created(sender, email, **kwargs): pass

@receiver(phone_created)
def hdl_phone_created(sender, phone, **kwargs): pass

Has you can see, this will bring us with a lot of instances and imports, making our application bigger and slow to start.

So I came up with the idea to make things more automated. Using only one instance (which I preferred to call it event) of Singal for each module. All signals (specifically, the keys) will be registered at runtime and only when needed.

First, I'll show you how to use it (it's beautiful ❤️) then I'll show you how I implemented it. You can choose to implement it the same way or use it to do your own implementation.

Using Event

I created a file named events.py in each module that has an instance of the global Event class.

# in: myproject.user.events

# I implemented the global Event class in the core module.
# Which contains all the classes shared between other modules.
from myproject.core.events import Event

EVENTS: dict = {
    'ACCOUNT_CREATED': 'user:account:created',
    'EMAIL_CREATED': 'user:emails:created',
    'PHONE_CREATED': 'user:phones:created'}

event = Event(events=EVENTS)

As you can see, the structure of the event dictionary is quite simple. Where key is the name of the event accessed in the instance and the value is the name of the event sharing between modules or systems. In case the event is being sent to an Event Queue

Due to this fact (events can be shared across systems) it is important to create a naming pattern to avoid duplicates and better grouping. I chose the following pattern:

<app|module|service name>:<context>:<action created|changed|deleted|viewed>

Some thing like: user:account-primary-email:changed

Continuing, I demonstrate below in a view how an event can be emitted:

# in: myproject.user.views

# Just import the event instance
from myproject.user.events import event

def create_user_view(request):
    # ... user creation logic
    user = User.objects.create()
    # emitting the event/signal
    event.send(event.n.ACCOUNT_CREATED, user=user)
    # or 
    event.send(event.name.ACCOUNT_CREATED, user=user)

The attribute n in the event, which can also be accessed via name, contains the name of the event previously defined in the EVENTS dictionary. This name is used as a sender when sending the event/signal.

Now, let's see how to handle the events

# in: myproject.user.signals

# Just import the signal receiver and the event instance
from django.dispatch import receiver
from myproject.user.events import event

@receiver(event, **event.EMAIL_CREATED)
def hlr_email_created(sender, email, **kwargs):
    print('Email Created! ', email)
    # do some quick task
    # Later we can do something like that
    enqueue(
        queue='default',
        event_name=event.n.EMAIL_CREATED,
        data=email)

@receiver(event, **event.ACCOUNT_CREATED)
def hlr_email_created(sender, user, **kwargs):
    print('Account Created', user)

Pay close attention and be careful, in two cases you will access the dictionary key defined in events.py.

First, you need to access the event name (E.g: to send a signal or send the event to the Event Queue).
Second, you need the necessary arguments to connect the function called to execute the event.

In the first case, you access the event name by the attribute n or name of the Event instance: event.n.ACCOUNT_CREATED

In the second case, you access the arguments directly from the instance event.ACCOUNT_CREATED

And that's it, and now let's see how I implemented it.

Event class Implementation

I will show the complete class with some details that I thought it was important to be commented on to facilitate the perception.

# in: myproject.core.events

import uuid
from django.dispatch import Signal

"""
First, I had defined this class to be able to access
dictionary key with dot (event.) in event
name or n attribute.
"""
class DictAsObject:

    defaults: dict

    def __init__(self, defaults: dict) -> None:
        self.defaults = defaults or dict()

    def __getattr__(self, attr: str):
        try:
            value = self.defaults[attr]
        except KeyError:
            raise AttributeError("Invalid key: '%s'" % attr)
        setattr(self, attr, value)
        return value

"""
Then I had define the Event class that inherits
from django.dispatch's Signal class
"""

class Event(Signal):

    __n: DictAsObject

    def __init__(self, providing_args: List[str] = None, use_caching: bool = False, events: dict = dict()) -> None:
        super().__init__(providing_args=providing_args, use_caching=use_caching)
        self.__n = DictAsObject(events)

    def __getattr__(self, attr: str):
        """
        Looks the event name by key in __n DictAsObject 
        instance and cache it on instance
        with the kwargs to django dispatch receiver:
            sender: event name
            dispatch_uid: unique id for event (event name too)
        """
        try:
            event_name: str = getattr(self.__n, attr)
        except AttributeError:
            raise AttributeError(_("the '%s' event was not registered") % attr)
        else:
            kwargs = dict(sender=event_name, dispatch_uid=str(uuid.uuid4())))
            setattr(self, attr, kwargs)
        return kwargs

    @property
    def n(self):
        return self.__n

    @property
    def name(self):
        return self.__n

And that's it, I hope you enjoyed it and that it's useful for you. If you have any criticisms or suggestions, don't hesitate to leave them in the comments. Maybe some disadvantage or advantage that I haven't mentioned...

If it was helpful or if you found it interesting, also leave an 🙋🏽‍♂️❤️ in the comments. Thank you, looking forward to the next article. Enjoy and follow my work.

See Here, all my resources.
Learn With Me on Youtube.
Follow Me on Instagram to stay updated.

Thanks,
Stay safe!