A Complete Guide to Web Development in Python

This article was written be Aaron Xie and was originally upublished at Educative.

In the past few years, Python has exploded in popularity. The programming language has surpassed Java in popularity, but, for many, this is no surprise. With the rise in machine learning, data analysis, and web application development, many developers increasingly utilize Python due to its powerful and abundant libraries, easy-to-learn syntax, and portability. Without a doubt, it’s a great time to be a Python developer. Today, you will learn how Python is utilized in web development.

We will cover the following:

• What is web development?
• What makes Python suited for web development?
• Python web frameworks
• Python libraries for web development
• A roadmap for web development with Python
• How to create your first web application in Python
• Become a Python web developer
• Resources

What is web development?

For those new to programming, you might be wondering what exactly web development is. Though it’s impossible to pinpoint an exact term, web development is loosely defined as building, creating, and maintaining websites. Typically, web development involves a frontend, everything that interacts with the client, and a backend, which contains business logic and interacts with a database.

Want a good overview of web development before continuing? Check out our Beginner's Guide to Web Development article.

What makes Python suited for web development?

Advantages of developing web applications in Python

• Easy to learn: Python is the most popular language for first-time learners for a reason. The language relies on common expressions and whitespace, which allows you to write significantly less code compared to some other languages like Java or C++. Not only that, but it has a lower barrier of entry because it’s comparatively more similar to your everyday language so you can easily understand the code. Now, this doesn’t mean that learning Python will be easy if you’re just starting. Programming, in general, isn’t easy, but it will mean that you can grasp concepts at a faster pace.

• Rich ecosystem and libraries: Python offers a vast range of library tools and packages, which allows you to access much pre-written code, streamlining your application development time. For example, you have access to Numpy and Pandas for mathematical analysis, Pygal for charting, and SLQALchemy for composable queries. Python also offers amazing web frameworks like Django and Flask, which we’ll dive into later in the article.

• Fast prototyping: Because Python takes significantly less time to build your projects compared to other programming languages, your ideas come to life a lot faster, allowing you to gain feedback and iterate quickly. This quick development time makes Python especially great for startups who can hit the market sooner to gain a competitive edge.

• Wide-spread popularity: Python is one of the most popular languages in the world, with communities from all over the world. Because of how popular the language is, Python is continuously updated with new features and libraries, while also providing excellent documentation and community support. Especially for new developers, Python provides extensive support and framework for one to begin their developer journey.

Other languages suited for web development

• Javascript is widely popular in web development because of its applicability to the frontend and the backend. JS frameworks like React.js and Vue.js are extremely popular on the frontend, while Express.js is increasingly used for the backend.

• Java is also very popular, especially in enterprise companies. Many companies use the Java Spring framework, which is a collection of libraries and configurations that helps build backend environments and deploy applications.

• Ruby is heavily used for server-side technology even though it’s considered an “older” technology compared to Javascript and Python for web development. The language is very opinionated, meaning that it assumes you will write code a certain way, and you must adhere to their structure.

• PHP is also a popular language within web development even though it has decreased in popularity in the last few years. It offers a ton of frameworks and integrations, but many developers believe that it has a poor design and identity, which makes it easy to write bad code.

Python web frameworks

What are web frameworks, and why are they important?

Think of a toolbox. A web framework is a collection of packages and modules made up of pre-written, standardized code that supports the development of web applications, making development faster and easier, and your programs more reliable and scalable. In other words, frameworks already have built-in components that “set up” your project, so you have to do less grunt work.

Python web frameworks are only utilized in the backend for server-side technology, aiding in URL routing, HTTP requests and responses, accessing databases, and web security. While it is not required to use a web framework, it is extremely recommended because it helps you develop complex applications in significantly less time.

What are some popular Python web frameworks?

Django and Flask are, by a wide margin, the most popular Python web development frameworks

Django is a Python web framework that offers an open-source, high-level framework that “encourages rapid development and clean, pragmatic design.” It’s fast, secure, and scalable. Django offers strong community support and detailed documentation.

The framework is an inclusive package, in which you get an admin panel, database interfaces, and directory structure right when you create the app. Furthermore, it includes many features, so you don’t have to add separate libraries and dependencies. Some features it offers are user authentication, templating engine, routing, database schema migration, and much more.

Django is incredibly flexible in which you can work with MVPs to larger companies. For some perspective, some of the largest companies that use Django are Instagram, Dropbox, Pinterest, and Spotify.

Flask is considered a microframework, which is a minimalistic web framework. It’s less “batteries-included,” meaning that it lacks a lot of features and functionality that full-stack frameworks like Django offer, such as a web template engine, account authorization, and authentication.

Flask is minimalistic and lightweight, meaning that you add extensions and libraries that you need as you code without automatically being provided with it by the framework. The philosophy behind Flask is that it gives only the components you need to build an app so that you have the flexibility and control. In other words, it’s un-opinionated. Some features it offers are a build-int dev server, Restful request dispatching, Http request handling, and much more.

Flask is also a prevalent and powerful web framework as it’s used by large companies like Netflix, Linkedin, and Uber.

Other notable frameworks

• Pyramid

• Web2Py

• Turbogears

Which should you use?

So, you might ask yourself: what framework should I choose? The answer is that it depends. Consider your skill level as a web developer. If you are quite experienced, consider developing your program with something more “barebones.” Whereas if you are a junior dev, it might be better to use a framework that provides more support like Django.

Also, ask yourself, would you prefer a “foundation” codebase to build off or have the flexibility to build the backbone of your codebase? If you prefer the first option, go with Django; if you prefer the second option, go with Flask. At the end of the day, they can both achieve the same functionality, and it’s more important to start coding rather than fretting over which framework is better.

Python libraries for web development

Some useful Python libraries for web development to keep note of:

• If you ever need a web crawler to extract data for your application, Scrapy is great for that. It's a widely used library for scraping, data mining, automated testing, and more.

• Zappa is a powerful library for developing a serverless application on AWS Lambda.

• Requests is a library that allows you to send HTTP requests easily, which is used to communicate with an application, allowing you to get HTML pages or data, for example.

• Another useful library is Dash, which helps those developing web applications that have to do with data visualization. Built on top of Flask, it offers features like charts, graphs, dashboards, and more.

A Roadmap for Web Development with Python

Step 1: HTML + CSS

When you're starting with web development, it's important that you first learn HTML and CSS, which are the fundamentals of learning how to build websites. It would be best if you learned how to structure responsive static pages to start your web development journey. It might also be helpful to learn concepts like the internet, HTTP, browsers, DNS, hosting, and more.

You can also learn a CSS framework like Materialize or Bootstrap, which significantly speeds up your development, but it's not needed.

Step 2: Javascript

An excellent next step is to learn vanilla Javascript. You should learn basic concepts like data types, variables, general conventions, string manipulation, arithmetic and operators, control statements, loops, etc. Learning the basics of Javascript will make it easier for you when you're applying Javascript to the client-side code.

Become a frontend developer.

Educative's frontend developer course track teaches you how to use HTML, CSS, and Javascript so that you can develop dynamic websites. The track is an ideal place to start, organizing courses in a natural progression, so you won't miss the need-to-know concepts!
Become a Front End Developer

Step 3: DOM & jQuery

After you learn javascript fundamentals, you should learn how to manipulate the DOM and jQuery, which is a javascript library that makes DOM manipulation easier. Now you know how to create dynamic pages.

Frontend Framework (optional)

While it's not required to learn a frontend framework like React to build a functional full-stack web application, it's recommended. Not only does it help you create beautiful SPAs, but it's also often a requirement to be hired as a front-end or full-stack developer.

Step 4: Python

Now, onto the backend. You should cover the basics of Python just like you did for Javascript before learning DOM manipulation. Learning the fundamentals will prepare you for Django, so you don't have as much head-ache jumping right in. Learning introductory Python shouldn't be too tricky, though, as many of the concepts will be similar to Javascript.

Step 5: Django + Database

With Django, you’ll be able to set up your backend environment and develop the business logic. You will also have to learn about databases such as SQLite, how to make queries, and the CRUD function. With this, you can make a full-stack application!

How to create your first web application in Python

You will create a Flask 'hello world' app as an introduction to Python web frameworks

Installing Flask

The first thing you need to do is install Flask. Depending on what version of Python you are using, you will have to use pip or pip3.

pip install flask

Flask app

Next, create a filed called hello.py with the following code.

from flask import Flask
app = Flask(__name__)

@app.route("/")
    def hello():
        return "Hello World!"

if __name__ == "__main__":
    app.run()

So what's happening here?

• Line 1 imports Flask

• Line 2 instantiates Flask with app variable, using the __name__ attribute

• Line 4 sets up a route / for your index, or default, page. When a user goes to locahost:5000/, you can set up particular code to be triggered

• Line 5 creates a function called hello

• Line 6 returns the string Hello World! to the user

• Line 8 tests to make sure the right script is being run

• Line 9 runs the application from the app variable we initialized so that the user can visit the web application by going to localhost

Become a Python web developer

Now, you should have a good overview of how Python operates within web development and its uses. With this understanding, you have many directions you can pursue when learning Python. If you’re ready to start learning and get your hands dirty, we recommend our free Learn Python from Scratch course, as well as our Flask course.

Resources

Here's a list of resources for you to learn more about web development with Python.

• Python Flask Tutorial: learn how to create a full-stack application with the Flask web framework
• Level up your Python skills: refresh your Python skills by reviewing the essential basics
• Learn Python in 5 steps: a step-by-step guide to learn Python by covering data types, conditionals, functions, loops, and data structures