Python Introduction to Web development using Flask

A good structure that contains complexity but can still be stringified is a Python dictionary. Therefore, I recommend that, whenever you want to send some data to the client, you choose a Python dict with whatever key-value pairs you need to convey information. To turn that dictionary into a properly formatted JSON response, headers and all, pass it as an argument to Flask’s jsonify function (from flask import jsonify).

The request.args.get() method is used to get the value of a query parameter. Here, we have defined three variables title, site_name, and message, and passed them to the render_template function as keyword arguments. In this file, a new Blueprint named ‘my_blueprint’ is created, and the views module is imported, ensuring that the routes are registered with the Blueprint. In this code snippet, we start by importing the Flask class from the flask module. Next, we create an instance of the Flask class, passing it the name of the module or package, in this case, __name__. The modular nature of the microframework that we mentioned earlier can come back to haunt coders, who will have to familiarize themselves with each constituent part.

Scaffold a Flask Project

You import the Flask class, giving the application access to the Flask functionality. Next, you connect the URL route “/” to the home() function by decorating it with @app.route(“/”). In this case, the home view returns a “Hello, World!” string that flask developer the browser can display. After you navigate to the project folder, it’s a good idea to create and activate a virtual environment. That way, you’re installing any project dependencies not system-wide but only in your project’s virtual environment.

• The new version that we just implemented starts by redefining the incomes variable into a list of Expenses and Incomes, now called transactions.
• From its lightweight design to its extensive ecosystem, Flask offers a seamless and efficient platform that empowers developers to create dynamic and innovative web applications.
• The choice between Flask and Django should consider project scale, required features, and development speed.
• If you’re not sure which to choose, learn more about installing packages.
• In addition to this, we also provide you with a list of Flask projects, FAQs, and interview questions for your future Interview.

Simplify deploying Flask applications with DigitalOcean App Platform. In the next section, you’ll leverage template inheritance to add consistent styling to your web project. Instead of adding the navigation menu code directly into base.html, you include _navigation.html in your website’s header. It ensures that users find the application not only convenient to use, but also enjoyable. The empty title block gives you the opportunity to extend the title with a child template. Then, you define two routes, one as the home view and the other as the about view.

Flask-Login: manages the user session and handles logging in and logging out and remembering logged-in users.

Check out Flask’s documentation for more information on how to use Jinja templates. In terms of learning Flask, it should not take you more than a few weeks at most to get a handle on the microframework, depending on your other commitments and your learning goals. There are a large number of handy video tutorials on YouTube and Udemy, as well as simple example projects provided by RealPython. Size is everything, and Flask’s status as a microframework means that you can use it to grow a tech project such as a web app incredibly quickly.

You use the python command line interface with the option -c to execute Python code. Next you import the flask package with import flask; then print the Flask version, which is provided via the flask.__version__ variable. You can reference a CSS file with a tag in the header of your HTML page. Just like before, you use url_for() to create the full URL for the href attribute. To link to the styles.css file stored in your Flask project’s static/ folder specifically, you use the filename argument. In Flask projects, you commonly save CSS files in a static/ directory.

Testing and Debugging Flask Applications

In fact, there are so many advantages of learning and using Python for web development. When it comes to developing a web app in Python, there’s a whole host of options available, but up there at the top of the list are Django and Flask. First, we’ll briefly go over the main ways in which web developers use Python in digital systems, then we’ll introduce the Flask microframework itself. The Hypertext Transfer Protocol (HTTP) is a protocol that allows clients and servers to share information. HTTP is a request-response protocol to communicate between a client and a server. A client (browser) sends an HTTP request to the server, and the server answers.

FastAPI follows a similar “micro” approach to Flask, though it provides more tools like automatic Swagger UI and is an excellent choice for APIs. However, as it is a newer framework, many more resources and libraries are compatible with frameworks like Django and Flask but not with FastAPI. Flask is a lightweight, micro web framework for Python created by Armin Ronacher. It offers a simple and subtle approach to web development, allowing developers to build web applications with minimal overhead. Flask offers a compelling choice for web development due to its micro framework architecture, which emphasizes simplicity and flexibility. Developers can customize their applications by integrating only the components they need, resulting in lean and efficient projects.

Project Setup

So, even when you decide to change the route to one of your pages, the navigation menu will still work. After importing Flask’s render_template(), you can use the function to return the home.html and about.html templates that you placed in the templates/pages/ folder. Blueprints are modules that contain related views that you can conveniently import in __init__.py. For example, you’ll have a blueprint that stores the main pages of your project. With the commands shown above, you create and activate a virtual environment named venv by using Python’s built-in venv module. The parenthesized (venv) in front of the prompt indicates that you’ve successfully activated the virtual environment.

This means that developers will have to manually add extensions such as libraries. And, if you add a huge number of extensions, it may start to slow down the app itself due to a multitude of requests. Mercifully pronounced “whiskey,” this stands for ​​Web Server Gateway Interface.