These are some of the most popular languages for web development, but did you know that many Web Developers use Python, too?
While people often associate Python with data science and analysis, it can also be a helpful tool for creating powerful web applications. In fact, you may have already heard of Flask and Django — two Python frameworks used to develop web apps.
But what exactly are Flask and Django, and why are they so popular?
In this article, we'll briefly introduce different types of Python frameworks. Then, we'll compare Django and Flask by going over:
- What each framework does
- How each framework works
- Why developers choose one over the other.
Read on to learn more about Flask and Django, or use the table of contents below to jump to a specific section.
- What's a Python framework?
- Types of Python frameworks
- What is Django?
- How a Django app works
- Advantages of Django
- Disadvantages of Django
- What is Flask?
- How a Flask app works
- Advantages of Flask
- Disadvantages of Flask
- When should you use Flask or Django?
- Getting started with Flask or Django
What's a Python framework?
A Python framework is a collection of packages and modules that help developers create web applications without having to worry about the details involved. Without frameworks, developers would need to code in low-level but critical essentials like protocols and sockets.
Imagine for a moment that you want to build a new house. You can certainly do it all yourself, but it's going to take a lot of time and effort.
Instead, you might build a pre-designed model home. While you have a few choices in the design, you're ultimately selecting from a group of choices presented by the architect. There's less flexibility, but you've saved yourself a lot of time.
That's how a Python framework works. Frameworks save developers a lot of time and allow them to focus on creating web apps without worrying about the time-consuming details.
How is a Python framework different from a Python library?
If you're familiar with Python, then the chances are that you've already seen multiple Python libraries. But how are libraries different from frameworks? In short, it all comes down to complexity.
Python libraries are collections of functions and methods that must be explicitly called by the developer. They're designed and organized to solve specific types of problems. For example, you could use a Python library for:
To use a baking analogy, think of a Python library as your flour. Now, imagine having to mill your own flour whenever you want to make bread. Isn't it so much easier and faster to buy flour at the store? And you're always in control of when you can buy flour and how much you can buy.
This is how a Python library works. Compared to Python frameworks, Python libraries provide a lot more flexibility, but it's still up to you to decide how to incorporate the library functionality into your overall structure.
Types of Python frameworks
Now that you understand what a Python framework is and how it differs from a Python library, let's focus on the two major types of frameworks used for web development: full-stack frameworks and micro-frameworks.
What is a Python full-stack framework?
As the name implies, a full-stack framework offers full functionality for both the front and back ends. Full-stack frameworks are regarded as one-stop solutions for everything you need for web app-building, including template layouts, form validation, and form generating.
What is a Python micro-framework?
Unlike full-stack frameworks, micro-frameworks (AKA lightweight frameworks) provide less functionality, particularly on the front end.
While a micro-framework offers more overall flexibility than a full-stack framework, anyone using this type of framework should be prepared to put more time into code development for their web app development project.
So, now that you understand the differences between full-stack frameworks and micro-frameworks, let's examine an example of each.
What is Django?
Django is a high-level, full-stack framework used for quickly developing clean-looking apps.
"High-level" means that Django is designed to minimize actual coding during the app design process. Instead of writing code, developers who use high-level frameworks can define options with forms, tables, and other interfaces.
The Django story
Django was created in 2003 by Web Developers Adrian Holovaty and Simon Willison. They began creating web applications using Python, and Django was born. Two years later, it was publicly released.
Django is named after Django Reinhardt, a famous Belgian-Romani jazz guitarist of the early- and mid-20th Century.
Today, Django is maintained by the Django Software Foundation and is one of the most popular Python frameworks for web development.
How a Django app works
To better understand how a Django web app works, let's consider four fundamental components of the app design pattern:
Like any well-designed website or web application, URLs in a Django-powered website should be systematically organized for easier content creation, search, and retrieval.
For example, in a simple blog that has content URLs organized by year, month, and day published, the URL "posts/2021/09/01" would retrieve the blog post published on September 1, 2021. Similarly, the URL "posts/2021/09" would retrieve an archive with links to all posts published in September, while the URL "posts/2021" would do the same for the entirety of 2021.
An article page may be laid out quite differently than a monthly or yearly archive page. The Django URL file is where you can define URL patterns that determine how the page will look based on the URL request.
The Django model
Django web apps manage data and communicate with databases through Python objects called models. For example, the data structure used in the web app is defined by the model, which can define characteristics like size, default values, and label texts for online forms.
The biggest value of the Django model is that it handles all communication with the database for you, saving you time on SQL coding.
Template files define the basic outline or structure of an application page. Templates can contain either:
- Predefined text elements.
- Placeholders that are later populated with information from the Django model.
Think of Django views as the central point of the web app design. Django views accept HTTP requests and output HTTP responses while working with the other components to dynamically create that HTTP output.
Django views coordinate with the URL file, model, and template files to create dynamic app content. While the content is based on the URL request pattern and information from the model, the template file determines formatting and layout.
If you're familiar with Python and looking to branch into web development, learning Django is a good place to start. Django offers some of the most complete and detailed documentation and tutorials. Plus, many cities have Django-specific support groups if you prefer to connect locally.
Even after you've mastered basic Django, there are plenty of resources to help you with its more advanced features, such as profiling and settings, caching, and working with Stripe to accept payments on your web app.
Advantages of Django
What does Django offer that makes it so popular and unique among all the other Python frameworks? Below are a few of Django's biggest advantages.
Django is fast
Django was designed to help developers create a web application as quickly as possible, from idea to release. So, it's ideal for developers working against tight production and release deadlines.
Django is full-featured
As a full-stack Python framework, Django includes plenty of features that you might need in your web app, from user authentication to RSS feeds.
Django is scalable
Django is designed to accommodate heavy traffic demands, which is one reason why this framework is so popular for large web applications.
Django offers versatility
Whether your web app is designed for content management, complex computing, or anything in between, Django can handle it.
Django is secure
One of the best parts about Django is that it comes with all the security features needed to protect your web application. The alternative would be for you, the developer, to think of every possible security issue and how to protect against it.
Disadvantages of Django
The more you read about Django, the more you must be thinking about how perfect it is for any project. Isn't there a catch? It turns out that there are a few disadvantages of Django that make it unsuitable in some situations.
Django is not for small projects
While Django comes as a full package, there's no way to separate anything out of that package if you just need a few features. So, Django can feel like overkill for small projects that have no plans to scale up.
Not only can the framework be confusing and overwhelming for developers of small projects, but all that Django coding takes up valuable bandwidth and server processing time.
Django runs in Python
Django is opinionated
It seems odd to think of code as being opinionated, but that's the technical term. A framework is opinionated when it's designed to be used in a particular way or according to particular assumptions.
While it's not impossible to use Django in a way other than what was intended by its designers, doing so will lead to a lot of extra work. This can make Django seem monolithic.
Now that you've got a basic understanding of Django's pros and cons, let's explore Flask.
What is Flask?
Flask is a micro-framework, meaning that it's designed to perform a more limited role than a full-stack framework like Django. But, as you'll find out, this isn't necessarily a bad thing.
The Flask story
Starting as an April Fool's joke in 2010, Flask was created by Armin Ronacher — a member of an international Python enthusiast group known as Pocoo. The project became a quick success, and the Pocoo team managed the development of Flask until 2016. After the team disbanded, the management of Flask was transferred to the Pallets Projects group.
Flask is named after an earlier Python micro-framework called Bottle. It's easily one of the most popular Python web-development frameworks, coming in just slightly behind Django in terms of the number of stars on GitHub.
How a Flask app works
As a micro-framework, Flask has few dependencies on external libraries compared to the full-stack Django framework. But, there are two big dependencies with Flask: Werkzeug and jinja2.
What is Werkzeug?
Werkzeug is a Web Server Gateway Interface (WSGI) utility library in Python. When you create a web application, you're focusing on using HTTP requests to create, query, and manage how content is put together.
But, another big part of an HTTP request is the web server, which handles details like network connections and actually receiving the request and sending the response. WSGI is a standard convention for creating and processing these requests with applications written in Python.
What is jinja2?
Remember how Django uses templates to create standard-looking pages that can be populated with custom text? Well, jinja2 is a Django-inspired template engine that helps you do the same thing in Flask.
Now that you understand the supporting dependencies behind Flask, let's look at the three main components of a Flask app: the Flask controller, the Flask model, and the Flask view.
The Flask controller
This is where you write the bulk of your web application code based on inputs and client requests. The controller is the central part of the Flask framework because it manages and changes the view and model based on client input to update what information is presented.
The Flask view
The Flask view is similar to a Django view in that it generates output in the form of content from the model presented and formatted based on a template file.
The Flask model
This is similar to a Django model in that it manages communication with a database. But, unlike Django, there's no included Flask model. It's up to the app developer to design a model to work with Flask's other components.
Advantages of Flask
As a micro-framework, Flask is designed to perform a few tasks extremely well. There are also other reasons why Web Developers choose Flask over other frameworks like Django. Let's take a look at some of Flask's biggest advantages.
Flask offers more flexibility
Compared to the opinionated Django framework, Flask is more flexible to different working styles and approaches to web app development. Programmers with more coding experience or who need more control of the app design prefer Flask for this reason.
Flask has more database support
Because Flask has no default model, it inherently supports multiple types of databases. This also makes databases easier to integrate into a Flask application.
Flask is easier to use for smaller applications
If you're looking to design a relatively simple web app with a few static pages, Flask will make your life easier than Django. For smaller web applications, many programmers find that Flask is easily scalable as well.
Disadvantages of Flask
Flask, just like Django, isn't perfect, and there are a few disadvantages that make it less popular in certain circumstances.
Flask isn't suitable for complex systems
If you're trying to build a complex web app with lots of dynamic pages, then Flask isn't the right framework to use. Over time, the maintenance costs and efforts will be much higher compared to a framework like Django, which is better suited for large projects.
Flask has less support than Django
This isn't to say that there isn't a large community of developers to answer questions when you run into a problem with your Flask application. But, the communities and documentation out there are a little smaller and harder to find compared to Django support resources.
When should you use Flask or Django?
Now that you understand the differences between Flask and Django and what each is used for, let's review why you should pick one over the other.
Use Django when:
- You're working on a large project.
- Deadlines are a driving factor.
- You want a one-stop solution that includes security and database management.
- You want to scale up to a more complex app later on.
- You need more online and community support.
On the other hand, you should use Flask when:
- You're working on a smaller, simpler web application.
- You need more coding flexibility.
- You want to incorporate more extensions and customized elements.
- You need API support in your web app.
- You want more control over database communication.
Getting started with Flask or Django
Regardless of which Python framework you prefer, what's important is that you start expanding your knowledge of web development by building a Python app with Flask or Django. Just remember that you should understand the basics of Python before creating your first app.
Once you've got the basics of Python down, learn how to use either framework in the courses below: