Python Web Development Tutorial

Python is one of the most frequently utilized programming languages to build web applications, making its use accessible for various tasks; including web development. Python offers various ways of building apps ranging from server-side web apps and RESTful APIs all the way up to serverless web apps and more! Because it offers such diverse use cases for building apps with Python it may seem intimidating or complicated when starting out; hence this blog aims to discuss Web development before diving deeper into how using it for Web development can benefit you.

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What is Web Development?

Web Development is a very vast field, but in general, it means developing applications that can be accessed via the internet on a web browser. A web application has two components, frontend, and backend.

Frontend

The frontend is the part of a web application that deals with what users can see and interact with and how those interactions should appear. It is what the users see on their web browser when they visit a URL to access a web application. The front-end developer of a web application is concerned with managing interactions with web servers, fetching data, displaying it in the web application, and sending it to the webserver to be saved or manipulated such as a tweet, blog post, etc.

Backend

Backend development with Python excels at serving server-side aspects of web apps. The backend manages storing, retrieving, and formatting data in a format agreed upon by other applications; for instance, storing information is stored locally so it can be parsed and understood by other programs over HTTP connections; therefore the backend must be capable of parsing an HTTP request and understanding its contents before taking appropriate actions on it – this includes operations like storing, validating, updating, deleting and retrieving.

One way of using these two aspects to create applications is to do everything on the server, from storing HTML, CSS and JavaScript on it to building templates using databases to populating them with data for templates to then sending off to browsers over networks – something which works fine with smaller applications but could significantly decrease performance for larger ones.

One way of accomplishing this task is using web servers to return data in a specific format, which is then parsed and displayed on the front end through templates using JavaScript by front-end developers. This reduces server processing and makes the job faster overall.

What makes Python suitable for Web Development?

In this blog, we will be making heavy use of Python because apart from being incredibly versatile and easy to use, Python has some distinct advantages that make it suitable for developing web applications. Let us now discuss web application development using Python.

Short Learning Curve

One of the reasons for Python being so popular is that it is very easy to learn. Python, as a programming language, was designed to be clear and concise. Its syntax is considered the primary reason for its readability. It emphasizes clarity over convention. Unlike other programming languages, such as Java, C#, or C++, where you have to write significantly more code, Python accomplishes something similar in less code, mainly because of the differences in syntax. Python favors indentation and natural English-like words, such as “and,” “not,” “none,” etc., as opposed to symbols and words, such as “&&,” “!” and “null,” that make other languages less readable and difficult to learn.

Rich Ecosystem

While developers build applications, there are some common problems that they face. They need to write code to solve several tasks, such as data validation, reading data from a CSV file, making a network request, etc. These tasks are common and also repetitive. Many developers end up writing libraries that are bundles of code that allow them to accomplish such tasks easily. These libraries are usually distributed on the internet so that other developers trying to solve similar problems can use the same.

Python has a large number of ready-made libraries for developers to use to solve numerous problems; developers can distribute their libraries as well. All these things allow developers to not focus on issues that are already solved but to use their time and energy to build applications and solve problems that are unique to them.

Development Speed

Since Python is easy to learn and understand, it rapidly increases the speed of development. As Python offers a lot of libraries, developers can put more focus on building applications. Python’s syntax and tooling also enhance development speed. This edge in the speed of development has been one of the major factors that have led to Python’s popularity.

However, Python is not suitable for the development of certain kinds of applications, such as device drivers, graphics software, etc., because Python is a high-level interpreted language and is slower than low-level languages, such as C, C++, etc. Nonetheless, for most software applications, the development speed is much more important than a small difference in execution speed. Hence, Python has gathered more popularity and is used in a variety of fields.

Large Community

Python has a large community of developers using it, which is because of its wide acceptance. The community has a lot of Python veterans and developers who have been using the language for quite a long time. Because of such a large community of developers, any questions that new developers have can be answered by these professionals with varying levels of proficiency in the language, which can help you learn web development with Python. Moreover, the issues that developers face when developing applications are either already resolved or will be resolved quickly as there are a large number of developers who are willing to help.

Python Web Frameworks

Frameworks are pre-written packages and modules bundled together to solve multiple common problems at once. This often requires tedious tasks like logging, validation and persistence for which developers must write code separately across each project – thus offering developers an efficient means of consistently solving these issues across projects through frameworks.

Python web application development typically employs Python frameworks to construct its backend. These tasks, including parsing HTTP requests and creating responses; accessing databases; authenticating users; authorizing access; etc. are so frequently employed that they are implemented on multiple backends.

Python Web development frameworks for backend development come in all shapes and sizes – from micro frameworks with specific tasks in mind to complex ones with many batteries included. Let us now examine some of the more popular ones.

Flask

Flask is one of the most popular HTTP Python Web Development Framework. Since it is a micro framework, it does not have a lot of features baked into it that other web frameworks might have, such as templating, account authorization, authentication, etc. However, this does not mean that Flask is a poor choice for you to use as it gives you the freedom to use any library or even custom code to deal with those concerns. For example, you can choose a custom ORM library to handle the database, and at the same time, you can use your code to deal with validating data. In other words, you are no longer tied down to always use a pre-built solution; rather, you can also choose to build your solutions.

Flask also allows you to build backend applications by mostly using those components that you wish to use. It only gives you the components that you need to build an app so that you have more flexibility and control and can make changes to the code base, such as switching to a different library, creating a custom package, etc. Flask is one of the most popular and powerful web frameworks, and it is used by huge companies including Netflix, LinkedIn, Uber, etc.

Django

Django is a Python HTTP framework for building the backend of web applications. It is a batteries-included framework that includes a lot of components, such as ORM, templating engine serializer, etc., for implementing various tasks. One of the reasons for Django’s popularity is that it is quite easy to learn and use, especially because of its pluggable architecture. Django allows you to build small decoupled apps that can be included or plugged into larger projects. In Django, you get apps and projects, where an app is a small self-contained codebase, while a project is a collection of multiple apps.

Django ships with some very powerful libraries for performing several tasks. One of the most popular among these libraries is the object-relational mapper (ORM.) An ORM is a software package that takes care of making database queries and mapping the results back to Python objects, which can be used inside a Python codebase. An ORM is easier to use with other Django libraries, including templating engine, validation, admin panel, etc. Django boosts developer productivity by allowing them to focus less on trivial low-level details and more on solving business problems. This is exactly what has made Django extremely popular.

Flask Vs. Django: Which one should you use?

Although both Django and Flask are extremely useful, determining when and how best to utilize each can be challenging. Both platforms can help build the backend for your web app.

However, each framework has specific use cases.

For instance, Flask may be ideal for experienced developers looking for something bare-bones with which they can build web apps quickly and cost-effectively.

Use it if you know some libraries but only require a framework to handle common web server tasks like HTTP communication and request parsing.

Django may be ideal if you are new to web development, taking on large projects without wanting to deal with low-level details, or do not wish to manage individual packages and integrate them later as it comes equipped with many packages out-of-the-box; you won’t have to deal with many integration and configuration tasks either.

How to build a Python Web Application using Flask?

Now that you have got an idea of how Python can be leveraged for web development, let us try and build a Flask application that will respond to a simple URL with Hello World. Before you start building the application, you need to install Flask using python-pip, which is Python’s package manager.

To do this, you need to, first, make sure that Python is installed using the following command:

python --version

Then, you have to open the command prompt and type in the following command to install Flask:

pip install flask

After installing Flask, type in the below code in a file, and save it as app.py.

from flask import Flask
app = Flask(__name__)

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

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

Now, let us try and understand the code line by line:

• Line 1: You import a class named Flask from the Flask package, which you will use to create the app.
• Line 2: You create an object of the Flask class and assign it to a variable named app. You also use the __name__ attribute to give your app a name.
• Line 4: You configure a route to “/” so that when you get a request for localhost:5000/, the code that is in Line 5 will get executed.
• Line 5: You define a function named hello.
• Line 6: You return Hello World! as a string response.
• Line 8: You make sure that the right script is being executed.
• Line 9: You run the application by using the Flask app object that you created in Line 2. Now, when users visit your application’s homepage, you can serve them with the correct response.

Now, to run the app, you need to open the command prompt or terminal in the same folder in app.py and run the following command:

• For Windows:

set FLASK_APP=app.py && flask run

• For macOS or Linux:

export FLASK_ENV=development

flask run

Watch out this video on How to Become a Web Developer

With that, we have come to the end of this blog. We have hopefully whetted your appetite to explore more on Python and web development. Python is an extremely useful language to learn, and we hope you continue on this Python journey.