7 Common Mistakes That Django Developers Make

Django is powerful web framework, but with power comes responsibility. In this article, we will cover common mistakes that are even seasoned Django developers make, yet most successful Django projects need to deal with these sooner or later.

1. Reinventing the wheel

Django has a lot of features out of the box and even more in third party packages. Try “Googling” a problem you want to solve before you write something - there’s probably a feature-rich solution that already exists.

You can also use online catalog Django Projects, where the category “apps” (small components used to build projects) has over 3200 projects. Here is a short sample of interesting packages just from the first two pages of the listing:

• Haystack modular search for Django
• Django-taggit simple tagging for Django
• Django-guardian per object permissions for Django
• Django-activity-stream generate generic activity streams from the actions on your site. Users can follow any actors’ activities for personalized streams.

2. Monolith application structure

Django is a loosely coupled framework and it doesn’t require you to build web applications in any particular way. Seasoned Django developers, however, have a standard way of doing things.

The fundamental unit of a Django web application is a Django project which is made up of one or more apps. A Django app is a self-contained package that should only do one thing. For example a blog, a membership app or an event calendar.

Django apps can contain Python modules, Django-specific modules (views, URLs, models, forms, etc), static files, database migrations, management commands, unit tests, and more. You should divide your project into small, reusable applications using simple logic.

\ecommerce_project      <= This is your Django project
    \cart               <= This is a Django cart app
    \checkout           <= This is a Django checkout app
    \products           <= This is a Django products app
    db.sqlite3          <= Your project database
    manage.py           <= Django project management utility

Using such a structure, related functionality will be closer together, allowing you and your team to see the bigger picture of your application more clearly. On top of that, you can export the application into another project and use it again, or even publish it on PyPi as an open-source module.

3. Writing fat representations and thin models

Django’s architecture can be described as a Model-Template-View (MTV) or Model-View-Template (MVT).

The model is where most of your business logic should go. It is defined in models.py and resides in the application directory. It also includes database queries that pass results to your view and template layers.

Views consist of code that deals with user interaction like form submission by the user and shaping results from the database to fit your template. It is defined in views.py.

If you don’t write your application logic in models and use views, this means you’ve written your code in a model based on the view. This makes the views “fat”, and the model “skinny.” Models should be fat and views should be skinny.

You should also leverage custom managers. For example, a custom manager can provide method with_counts(), which returns a list of all OpinionPoll objects, each with an extra num_responses attribute that is the result of an aggregate query. For more ideas, check the build-in UserManager.

4. Too many queries per view, or unoptimized queries

Django’s ORM is often blamed for making too many queries, or unoptimized queries. But we see that happening with ORMs in other frameworks as well.

The real problem is we are often unaware of the performance problems and their sources. Once you find out what your bottlenecks are, you’ll be able to choose the right approach to address them. There’s a lot you can do from here, but most likely it’ll be:

• Fix plain-broken ORM queries (hello prefetching)
• Tweaking and optimizing ORM queries
• Add caching in the right places
• Provision more resources

django-debug-toolbar is an amazing debugging tool. You can use it to track down performance problems in SQL queries, requests, templates, cache, etc. This little package will help you identify the problems quickly. I highly recommend using it.

5. Redundant model fields

Since queries can’t use computed columns and adding a real column is only a “make migrations” away, often developers duplicate fields that represent the same data in different ways.

Pretty soon half of your Vehicles have is_motorcycle == True and wheel_count == 4, and you’re not sure which field to trust (hint: neither).

With Django, you can refactor inconsistent properties like this with the @property decorator. However, while the ORM allows you to access columns as properties, the reverse is not true, so you have to manually refactor every query.

6. Not adding indexes on models

Even seasoned Django developers forget about indexes. Please, do add indexes to your models! On the other hand, do not index everything, as it will slow down inserts, updates, and deletes. As a general rule, you want an index on anything you will use to filter or join on. Analyze your QuerySets to determinate where indexes are needed.

7. Inconsistent data validation

Django models can be associated with one or more “forms”, which used to create and update model instances. Forms have a lot of default behavior, particularly validation, which is controlled by the properties of the model. In fact, many properties of the model exist only to control the forms’ default behavior.

Many Django developers forget the model can be modified not only through its form. They also forget about keeping track of which constraints are where. Non-null? That’s on the model. Define choices on a field, explicitly enumerating what values it can have? That’s on the form. Uniqueness? On the model. And so on.

This inconsistent validation results in bad user experience: forms, pre-populated with the existing data for an object, that cannot be submitted because the existing data is invalid.

Summary

Django was crafted to help build software as quickly as possible. However, when rushing with adding new features it is easy to forget something or loose the big picture. In this article, we will looked at some common mistakes that are often made by Django developers and ways to avoid them.

This checklist should useful even if you’re a skilled Django developer because mistakes, like not adding indexes on models or inconsistent data validation, aren’t just limited to new developers.

#Django #Python

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4 key Features of Django Framework that Make it the Best Amongst all!

Django is one of the popular python based open-source web frameworks mainly used by the developers who like to have rapid development along with the clean pragmatic design.

Read this blog to know the various Django Features with details.

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Django admin full Customization step by step

Welcome to my blog , hey everyone in this article you learn how to customize the Django app and view in the article you will know how to register  and unregister  models from the admin view how to add filtering how to add a custom input field, and a button that triggers an action on all objects and even how to change the look of your app and page using the Django suit package let’s get started.

Database

Custom Titles of Django Admin

Exclude in Django Admin

Fields in Django Admin

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Why should you use Django for Web Development?

Django is a highly powerful framework for building small and large scale web applications. Being a Python-based framework, Django for web development is the preferred choice of companies all over the world. 

If you are looking for proof of Django’s popularity, here it is - Django framework for web development is used by YouTube, Dropbox, Instagram, Pinterest, Google, Reddit, and many more. Being an open-source and maintainable web application development framework, companies adore it for building dynamic and sophisticated web applications. 

Now you must be asking yourself “is Django good for web development?” The framework has a lot of benefits over other frameworks like Ruby on Rails, Flutter, Xamarin, etc. When you want a robust, scalable and stable application with a large codebase, using Django for web development is the right choice. 

Read more: Pros and Cons of Django Web Framework for App Development

What are the advantages of using Django for web development?

Django is admired by web developers all over the world. It is an easy-to-use battery including a framework that doesn’t eat up a lot of time in configuration and setting up the development environment. 

The following benefits are your answer to  “why use Django for web development”:-

1. Simplicity
   Django framework for web development is excellent because of its simplicity and the ease of use. It allows developers to do more than one iteration and make modifications without running the entire code from scratch.
   
   Apart from that, it makes development simpler with its Don’t Repeat Yourself Philosophy, allowing developers to reuse the codebase for creating different components.

2. Ecosystem
   Django has a rich and diverse development ecosystem. It permits a lot of third-party apps and integrations. While setting up the ide for Django web development, you can use the third-party apps and integrations to add components or blocks in the web application.
   
   From authorization to sending emails, there are apps for some of the most common features. It reduces the time taken to write code for these programs and leads to the timely delivery of products.

3. Documentation
   Django for web development comes with excellent documentation to develop real-world applications. While other frameworks have alphabetical lists and modules, Django provides quick references to developers for building applications from different stages in the process.
   
   The documentation is updated regularly as Python programmers add new exceptions, rules, and features to the open-source framework. While it is hard to keep it fine-tuned, it is one of the best documentation of a framework.

4. Wide community
   If you are still asking what are the advantages of using Django for web development, then look at its wide community of developers. Django developers are increasing every day as the framework becomes a popular choice amongst enterprises to fulfill their web application needs.
   
   The community is ready to assist on all Python Django web development projects. There are regular meets, tutorials, and material that can help anyone working with Django. The community regularly answers queries, and you can find the solution to almost any Django problem.

5. Libraries
   Django allows developers to use massive amounts of libraries for building feature-rich and functional applications. Django REST framework is an excellent library for building Application Programming Interfaces (APIs). Django CMS, Django-allauth, and many other libraries are used for adding functionalities to web applications.
   
   Since the framework uses Python, using libraries becomes an easy task. Python has a lot of libraries with Django integration that enables building quality applications.

Also Read: A Guide to Django Web Development for your Business

Start using Django for web application development

Whether you are looking for an ERP application or a B2C web app, Django framework for web development is the perfect solution. It allows you to develop scalable applications capable of handling heavy traffic load in the future.
You can hire Python developers and Django experts for Python development services from BoTree Technologies who can fulfill your web development needs.

Source: https://www.apsense.com/article/why-should-you-use-django-for-web-development.html

#python development services #django framework #django rest framework #django for web development #django for web development #django

How long does it take to develop/build an app?

With more of us using smartphones, the popularity of mobile applications has exploded. In the digital era, the number of people looking for products and services online is growing rapidly. Smartphone owners look for mobile applications that give them quick access to companies’ products and services. As a result, mobile apps provide customers with a lot of benefits in just one device.

Likewise, companies use mobile apps to increase customer loyalty and improve their services. Mobile Developers are in high demand as companies use apps not only to create brand awareness but also to gather information. For that reason, mobile apps are used as tools to collect valuable data from customers to help companies improve their offer.

There are many types of mobile applications, each with its own advantages. For example, native apps perform better, while web apps don’t need to be customized for the platform or operating system (OS). Likewise, hybrid apps provide users with comfortable user experience. However, you may be wondering how long it takes to develop an app.

To give you an idea of how long the app development process takes, here’s a short guide.

App Idea & Research

_Average time spent: two to five weeks _

This is the initial stage and a crucial step in setting the project in the right direction. In this stage, you brainstorm ideas and select the best one. Apart from that, you’ll need to do some research to see if your idea is viable. Remember that coming up with an idea is easy; the hard part is to make it a reality.

All your ideas may seem viable, but you still have to run some tests to keep it as real as possible. For that reason, when Web Developers are building a web app, they analyze the available ideas to see which one is the best match for the targeted audience.

Targeting the right audience is crucial when you are developing an app. It saves time when shaping the app in the right direction as you have a clear set of objectives. Likewise, analyzing how the app affects the market is essential. During the research process, App Developers must gather information about potential competitors and threats. This helps the app owners develop strategies to tackle difficulties that come up after the launch.

The research process can take several weeks, but it determines how successful your app can be. For that reason, you must take your time to know all the weaknesses and strengths of the competitors, possible app strategies, and targeted audience.

The outcomes of this stage are app prototypes and the minimum feasible product.

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Developer Career Path: To Become a Team Lead or Stay a Developer?

For a developer, becoming a team leader can be a trap or open up opportunities for creating software. Two years ago, when I was a developer, I was thinking, “I want to be a team leader. It’s so cool, he’s in charge of everything and gets more money. It’s the next step after a senior.” Back then, no one could tell me how wrong I was. I had to find it out myself.

I Got to Be a Team Leader — Twice

I’m naturally very organized. Whatever I do, I try to put things in order, create systems and processes. So I’ve always been inclined to take on more responsibilities than just coding. My first startup job, let’s call it T, was complete chaos in terms of development processes.

Now I probably wouldn’t work in a place like that, but at the time, I enjoyed the vibe. Just imagine it — numerous clients and a team leader who set tasks to the developers in person (and often privately). We would often miss deadlines and had to work late. Once, my boss called and asked me to come back to work at 8 p.m. to finish one feature — all because the deadline was “the next morning.” But at T, we were a family.

We also did everything ourselves — or at least tried to. I’ll never forget how I had to install Ubuntu on a rack server that we got from one of our investors. When I would turn it on, it sounded like a helicopter taking off!

At T, I became a CTO and managed a team of 10 people. So it was my first experience as a team leader.

Then I came to work at D — as a developer. And it was so different in every way when it came to processes.

They employed classic Scrum with sprints, burndown charts, demos, story points, planning, and backlog grooming. I was amazed by the quality of processes, but at first, I was just coding and minding my own business. Then I became friends with the Scrum master. I would ask him lots of questions, and he would willingly answer them and recommend good books.

My favorite was Scrum and XP from the Trenches by Henrik Kniberg. The process at D was based on its methods. As a result, both managers and sellers knew when to expect the result.

Then I joined Skyeng, also as a developer. Unlike my other jobs, it excels at continuous integration with features shipped every day. Within my team, we used a Kanban-like method.

We were also lucky to have our team leader, Petya. At our F2F meetings, we could discuss anything, from missing deadlines to setting up a task tracker. Sometimes I would just give feedback or he would give me advice.

That’s how Petya got to know I’d had some management experience at T and learned Scrum at D.

So one day, he offered me to host a stand-up.

#software-development #developer #dev-team-leadership #agile-software-development #web-development #mobile-app-development #ios-development #android-development