Flask is a micro web framework for Python that makes it easy to build web applications quickly. It is lightweight, flexible, and comes with essential tools needed for web development. Flask is widely used in modern web development, especially for building REST APIs and small to medium-sized applications.
Why Flask?
Flask is an excellent choice for beginners and experienced developers due to its simplicity, flexibility, and extensibility. It follows the "micro" approach, meaning it provides the core functionality while allowing developers to add extensions based on their needs.
1. Lightweight and Minimalistic
Flask does not include unnecessary components, making it fast and efficient. You only install what you need, keeping your app lean.
2. Built-in Development Server & Debugger
Flask provides an inbuilt development server with debug mode, which helps developers quickly test and debug their applications.
3. Routing System
With Flask, you can easily define routes to handle different URLs using decorators.
Example:
from flask import Flask
app = Flask(__name__)
@app.route("/")
def home():
return "Hello, Flask!"
if __name__ == "__main__":
app.run(debug=True)
This creates a simple web server that returns "Hello, Flask!" when accessed.
4. Jinja2 Templating
Flask uses Jinja2, a powerful templating engine that allows you to create dynamic HTML content.
Example:
<h1>Welcome, {{ username }}!</h1>
5. RESTful Request Handling
Flask provides built-in support for handling GET, POST, PUT, and DELETE requests, making it easy to build RESTful APIs.
Example:
from flask import request
@app.route("/api", methods=["GET", "POST"])
def api():
if request.method == "POST":
return {"message": "Data received!"}
return {"message": "Welcome to the API!"}
6. Extensible with Flask Extensions
Flask-SQLAlchemy – Database integration
Flask-WTF – Form validation
Flask-Login – User authentication
Flask-RESTful – API development
7. Middleware and Hooks
Flask allows middleware and request hooks to process requests before and after they are handled by views.
8. Easy Integration with Frontend Frameworks
Flask seamlessly integrates with frontend frameworks like React, Vue, and Angular to build full-stack applications.
When to Use Flask?
Small to Medium Web Applications
REST API Development
Prototyping & MVPs