Flask Framework in Python: A 2023 Beginner's Guide

Flask is a popular web application framework for Python. It allows developers to build web applications quickly and easily by providing a lightweight and modular approach to web development. Flask is based on the Werkzeug toolkit and the Jinja2 template engine, and it is licensed under the BSD license.

Flask is known for its simplicity and ease of use, making it a popular choice for building small to medium-sized web applications. It provides developers with a range of features, including routing, debugging, and built-in support for unit testing.

Some of the key features of Flask include:

  • Routing: Flask allows developers to map URLs to functions or methods, making it easy to create URLs for different pages of a web application.
  • Templating: Flask uses the Jinja2 template engine to render dynamic HTML pages with dynamic content.
  • Built-in server: Flask comes with a built-in server for development purposes, so developers can easily test their web applications without the need for additional software.
  • Debugging: Flask includes a debugger that helps developers to quickly identify and fix issues in their code.
  • Extensions: Flask has a wide range of extensions available, which can be used to add additional functionality to the framework.

Overall, Flask is a powerful and flexible web application framework for Python that is ideal for building small to medium-sized web applications quickly and easily.

How to Install and Use Flask in Python: A 2023 Step-by-Step Guide for Beginners

You can install Flask by following these steps:

  1. Open a command prompt or terminal window.
  2. Type pip install Flask and press enter.
  3. Wait for the installation to finish.

Once Flask is installed, you can create a simple application to test it out. Here's an example:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello, World!'

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

Save this code in a file called app.py. Then, run the following command in your terminal:

python app.py                          

This should start a local web server and print a message telling you that Flask is running. You can then visit http://localhost:5000/ in your web browser to see the "Hello, World!" message.

You can customize your Flask application by adding more routes, templates, and functionality. Flask has a lot of documentation and examples available online, so don't be afraid to explore and experiment!

Discover the World of Flask | Build a Web App with Python Flask

Learn how to build a web app using Python Flask. Our step-by-step guide will show you how to create a sign-up form, a landing page with a gradient background, and more. Start your journey to discover the world of Flask today!

First, create a new directory for your project and navigate to it in your terminal/command prompt.

mkdir flask_web_app
cd flask_web_app

Create a virtual environment for your project to keep its dependencies separate from other Python projects on your system:

python3 -m venv env
source env/bin/activate    # On Unix or Linux
env\Scripts\activate      # On Windows

Install Flask and its dependencies:

pip install flask

Create a new file called app.py in your project directory, and add the following code to it:

from flask import Flask, render_template, request

app = Flask(__name__)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/signup', methods=['POST'])
def signup():
    name = request.form['name']
    surname = request.form['surname']
    email = request.form['email']
    password = request.form['password']
    # Add code here to store the user's information in a database or file
    return render_template('signup.html', name=name)

if __name__ == '__main__':
    app.run(debug=True)


Create a new directory called templates in your project directory, and add two new HTML files to it: index.html and signup.html.

In index.html, add the following code to create a landing page with a gradient background:


<!DOCTYPE html>
<html>
  <head>
    <title>Flask Web App</title>
      <style>
          body {
              background: linear-gradient(to bottom right, #1a1f36, #681c72);
            }
      </style>
  </head>
  <body>
      <h1 style="text-align: center; color: white;">Let's discover the world of Flask!</h1>
      <form action="/signup" method="post" style="margin: 0 auto; width: 50%;">
          <label for="name">Name:</label><br>
          <input type="text" id="name" name="name"><br>
          <label for="surname">Surname:</label><br>
          <input type="text" id="surname" name="surname"><br>
          <label for="email">Email:</label><br>
          <input type="email" id="email" name="email"><br>
          <label for="password">Password:</label><br>
          <input type="password" id="password" name="password"><br><br>
          <input type="submit" value="Sign up">
      </form>
  </body>
</html>

In signup.html, add the following code to display a message confirming the user's sign-up:

<!DOCTYPE html>
<html>
    <head>
        <title>Flask Web App</title>
        <style>
            body {
                background: linear-gradient(to bottom right, #1a1f36, #681c72);
                }
        </style>
    </head>
    <body>
        <h1 style="text-align: center; color: white;">Thank you for signing up, {{ name }}!</h1>
        <a href="/" style="color: white;">Return to homepage</a>
    </body>
</html>

Run your Flask:

python app.py

Overall, we learned how to build a web app using Python Flask. By following our step-by-step guide, you can create a sign-up form and a landing page with a gradient background. With these skills, you can start exploring the endless possibilities of Flask and develop your own web apps. Start your journey to discover the world of Flask today and take your coding skills to the next level!

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