DigitalOcean
digitalocean.com › community › tutorials › how-to-make-a-web-application-using-flask-in-python-3
Build a Flask Python Web App from Scratch | DigitalOcean
November 6, 2025 - In this step, you’ll make a small web application inside a Python file and run it to start the server, which will display some information on the browser. In your flask_blog directory, open a file named hello.py for editing, use nano or your favorite text editor: ... This hello.py file will serve as a minimal example ...
GeeksforGeeks
geeksforgeeks.org › python › flask-creating-first-simple-application
Flask - Creating First Simple Application - GeeksforGeeks
January 7, 2026 - from flask import Flask app = Flask(__name__) @app.route('/') def hello_world(): return 'Hello World' if __name__ == '__main__': app.run() ... Open the given URL in your web browser to view your first Flask web page showing Hello World.
Real life examples of complex applications
I think I don't need blueprints, because I don't have any templates to separate from the other things. I just don't want to bunch all my routes together in a huge file, like.. all the examples on the internet do. Modularizing routes so they're not in one monolithic file is exactly the purpose of blueprints, so I would suggest revisiting them. More on reddit.com
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October 18, 2022Stay with Python (Flask) or learn JavaScript for web app?
In this context, by JavaScript, you're really talking about Node. Without further context, though, there really isn't any compelling reason to choose one over the other. Here are some considerations, in no specific order. Node is built from the ground up to be non blocking. This is why it can be perceived as faster, especially for single threaded application. Every request you make is async by default. This is optional in Python. If you're accustomed to "blocking" languages, it will take some getting used to. You can famously end up in "callback hell" if you don't account for this. Modern Node supports TypeScript, which is arguably more robust, or at least more cohesive, than Python's typing libraries. Typing is either a pain in the ass or crucial, depending on your needs. With Flask, you'll have to contend with WSGI or ASGI if you want async, which requires nontrivial configuration. If you're just building a REST API, you may want to look into AWS API Gateway. In simplistic terms, this is Flask as a service. Then you can answer requests with Lambdas, which can either be pure Python or Node. You could even alternate between the two depending on the request; though, I wouldn't recommend that. Although you'll find benchmarks all over the place comparing language performance, it's not meaningful in real world applications. 99% of the time, your bottleneck will be I/O, likely from a database, not your language. But if you really want to butt heads on the performance argument, Python supports multi processing, multi threading and async, while JavaScript is strictly async. From a stability standpoint, Python versions have fewer changes and fewer versions. This can help when you're seeking answers to questions that may have been answered years ago. Made a mobile app with Python and turned out to be garbage compared to using Kotlin Yeah, mobile apps are an entirely different ball of wax. Especially given Google's endorsement, it's difficult to make arguments for other languages on Android. More on reddit.com
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November 11, 2022I am confused a bit. Why should I use flask when instead I can use html, css and javascript to make an interactive webapp? I am confused how I should proceed with my project.
I think in your question you are revealing that there is quite a lot you haven't yet learned about building web software, so I welcome you to this journey and hopefully I can provide you with some information that will get you started. Can you build an app with just HTML, CSS, and JavaScript? Absolutely you can. And there are many useful applications you can build, but remember that these are technologies that are running only in your user's web browser (I will address Node separately). The web browser runs entirely on your user's computer, which means that information and interactions they use there will not be shared with you. Imagine for example that you want to have users "log in" to your website before they can use it? This is common of course on many web applications (such as reddit) where users need an account to interact. Where will this list of users live? How can it be accessed by everyone everywhere, without sharing the entire list with everyone all the time? The answer? The Backend. This is where tools like Flask come in handy. A Flask application runs on a web server that you control, instead of entirely on the users browser. Your Web Application (The front end) can be generated by Flask if you like, but it can also be completely separate. What's important is that when a user interacts with your web application, some of those actions will need to be sent to "the backend" in order to be processed. Flask is an excellent choice for building this (but not the only choice). There are alternatives to Flask you could consider if you like. For example, Node is a technology that allows you to run JavaScript on the backend. However here at r/Flask we tend to be Flask enthusiasts, and I'd say most of us are better positioned to help you with that. More on reddit.com
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June 10, 2019Where Can I Host My Flask Web App for Free?
www.pythonanywhere.com has a generous free tier
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July 30, 2023Videos
01:25:41
Flask Full Course: Build Stunning Web Apps Fast | Python Flask ...
11:20
First Flask Project - Flask Tutorial Series #1 - YouTube
How to Create a Web Application in Python using Flask - YouTube
01:00:08
Flask 101: A Comprehensive Guide to Getting Started with Flask ...
08:40
Creating a Scalable Flask Web Application From Scratch: Setting ...
Create A Flask Web App And Connect SQL Database - Python ...
Reddit
reddit.com › r/flask › real life examples of complex applications
r/flask on Reddit: Real life examples of complex applications
October 18, 2022 -
Are there some good examples of real applications (not hello world todo/blog post or tutorials) of Flask applications, from where a new flask user could learn best practices from?
Flask doesn't force any design patterns or specific ways to do anything on me, and that leaves me wondering about what are the best ways to do something. How do I split up the routes file from all-routes-in-a-file.py to something more manageable, how do I validate input requests coming from a JS front-end, what are the best practices for doing thing X and Y, that I haven't even thought about yet.
Background information: I am writing a back-end api for a Vue frontend, there are no templates in the flask app, I am using JWT for authentication already. I think I don't need blueprints, because I don't have any templates to separate from the other things. I just don't want to bunch all my routes together in a huge file, like.. all the examples on the internet do.
I have found some open-source flask examples, but they seemed to be doing something weird, or.. were really outdated.
Or should I just write my back-end in Java and Spring, since that is used at work, and I can steal ideas and patterns from work projects? Wanted to use flask, to not have to deal with the massiveness of Spring and Java.
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I think I don't need blueprints, because I don't have any templates to separate from the other things. I just don't want to bunch all my routes together in a huge file, like.. all the examples on the internet do. Modularizing routes so they're not in one monolithic file is exactly the purpose of blueprints, so I would suggest revisiting them.
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For big projects you should follow these principles: https://hackersandslackers.com/your-first-flask-application There are 11 parts, each one explains how to structure and build the different things like logins, connection to a database, structuring everything with blueprints etc. I found it very helpful to make the jump from the usual single-file-apps to having a good structure where you split the project into meaningful and easy manageable parts. edit: Just read, that you don't need blueprints, so you might jump over that part, but i think it's good to learn it anyway in case you want to extend your project later on.
freeCodeCamp
freecodecamp.org › news › how-to-build-a-web-application-using-flask-and-deploy-it-to-the-cloud-3551c985e492
How to build a web application using Flask and deploy it to the cloud
October 7, 2024 - We are creating an instance of the Flask class and calling it app. Here we are creating a new web application. Line 5: It represents the default page. For example, if I go to a website such as “google.com/” with nothing after the slash.
Flask
flask.palletsprojects.com › en › stable › quickstart
Quickstart — Flask Documentation (3.1.x)
For a reference to HTML, CSS, and other web APIs, use the MDN Web Docs. To render a template you can use the render_template() method. All you have to do is provide the name of the template and the variables you want to pass to the template engine as keyword arguments. Here’s a simple example of how to render a template: from flask import render_template @app.route('/hello/') @app.route('/hello/<name>') def hello(name=None): return render_template('hello.html', person=name)
JetBrains
jetbrains.com › help › pycharm › creating-web-application-with-flask.html
Creating Web Applications with Flask | PyCharm Documentation
Application entry point that renders the scatter chart and provides links to the detailed summary of climate in a particular city. ... A series of pages with the detailed information about climate in each city. ... Authentication page. One needs to enter the valid credentials to edit meteo data. ... A series of pages for editing city-specific data. Each HTML page has a corresponding Flask view implemented in Python code.
GitHub
github.com › helloflask › flask-examples
GitHub - helloflask/flask-examples: Example applications for Flask learners. · GitHub
Cache (/cache): Cache with Flask-Caching. SayHello: A simple message board. Bluelog: A blog engine that supports category and resource management. Albumy: A full-featured photo-sharing social networking.
Starred by 232 users
Forked by 159 users
Languages JavaScript 50.6% | HTML 33.9% | CSS 10.5% | Python 4.7%
GitHub
github.com › pallets › flask
GitHub - pallets/flask: The Python micro framework for building web applications. · GitHub
# save this as app.py from flask import Flask app = Flask(__name__) @app.route("/") def hello(): return "Hello, World!" $ flask run * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit) The Pallets organization develops and supports Flask ...
Starred by 71.4K users
Forked by 16.8K users
Languages Python
Miguel Grinberg
blog.miguelgrinberg.com › post › the-flask-mega-tutorial-part-i-hello-world
The Flask Mega-Tutorial, Part I: Hello, World! - miguelgrinberg.com
In this case, the @app.route decorator creates an association between the URL given as an argument and the function. In this example there are two decorators, which associate the URLs / and /index to this function. This means that when a web browser requests either of these two URLs, Flask is going to invoke this function and pass its return value back to the browser as a response.
Real Python
realpython.com › flask-project
Build a Scalable Flask Web Project From Scratch – Real Python
March 22, 2024 - In this section, you’ll spin up a development server and display "Hello, World!" in the browser with just a few lines of code. Then, you’ll expand your project structure to prepare a scalable Flask web application.
Flask
flask.palletsprojects.com
Welcome to Flask — Flask Documentation (3.1.x)
There is also a more detailed Tutorial that shows how to create a small but complete application with Flask. Common patterns are described in the Patterns for Flask section. The rest of the docs describe each component of Flask in detail, with a full reference in the API section. Flask depends on the Werkzeug WSGI toolkit, the Jinja template engine, and the Click CLI toolkit.
Full Stack Python
fullstackpython.com › flask.html
Flask - Full Stack Python
Visualize your trip with Flask and Mapbox along with the open source flask_mapbox GitHub repository provides a fantastic example visualization of a trip to Iceland with Flask as the backend web framework. Microservices with Flask, Docker, and React teaches how to spin up a reproducible Flask development environment with Docker. It shows how to deploy it to an Amazon EC2 instance then scale the services on Amazon EC2 Container Service (ECS). Build a Video Chat Application with Python, JavaScript and Twilio Programmable Video shows how to use Twilio Programmable Video to build cross-platform (web, iOS and Android) video into Flask applications.
DEV Community
dev.to › cre8stevedev › building-a-full-stack-web-application-using-flask-python-web-framework-part-one-5b1i
Building a Full Stack Web Application using Flask (Python Web Framework) - Part One - DEV Community
April 11, 2024 - Debug mode ensures that our application restarts whenever we make changes to the files. Meaning you don't have to kill the server and relaunch again whenever you make a change. (myvenv) Tutorial$ curl localhost:5100; echo ""; <h1>This is the Home Page</h1> (myvenv) Tutorial$ Yaay! You just took the first step in launching a functional web server using flask.
Real Python
realpython.com › learning-paths › flask-by-example
Flask by Example (Learning Path) – Real Python
In this course, you’ll learn how to go from a local Python script to a fully deployed Flask web application that you can share with the world. ... Learn how to create a Python Flask example web application and deploy it using Heroku.
Raymond Camden
raymondcamden.com › 2025 › 01 › 13 › simple-blog-example-in-flask
Simple Blog Example in Flask
January 13, 2025 - To get an idea of how easy it is, here's the basic "hello world" from the quickstart: from flask import Flask app = Flask(__name__) @app.route("/") def hello_world(): return "<p>Hello, World!</p>"
CodingNomads
codingnomads.com › example-python-flask-app
Example Python Flask App: Microblog
microblog.py - The web app gets instantiated here and becomes the Flask application instance
Medium
medium.com › @AlexanderObregon › building-a-web-application-from-scratch-with-flask-and-python-f25f1f638aec
Building a Web App with Flask & Python | Medium
April 24, 2024 - Flask is a popular micro-framework in Python for creating lightweight and scalable web applications. In this walkthrough, we will build a web application from scratch using Flask and Python.
GitHub
github.com › XD-DENG › flask-example
GitHub - XD-DENG/flask-example: A minimal web app developed with Flask · GitHub
A minimal web app developed with Flask framework.
Starred by 118 users
Forked by 135 users
Languages Python 56.1% | HTML 43.9%
Medium
medium.com › @moraneus › python-flask-a-comprehensive-guide-from-basic-to-advanced-fbc6ec9aa5f7
Python Flask: A Comprehensive Guide from Basic to Advanced | by Moraneus | Medium
May 17, 2024 - In this example, @app.route('/welcome-astrunaut') tells Flask that whenever a web browser requests our URL ending in /welcome-astrunaut, it should be called the welcome_astronaut function and respond with "Welcome to the Interstellar Space Station!".
Teclado
python-web.teclado.com › section07 › lectures › 01_hello_world_flask
'Hello, world!' with Flask | Web Developer Bootcamp with Flask and Python
If you go to the Flask[5] website, you are welcomed with a very simple example application that has just five lines of code.