Flask: Core Concepts and Basic Applications
Flask is a lightweight Python Web framework with a "micro" design philosophy, featuring a streamlined core functionality that enables complex requirements through extensible components. Key reasons for choosing it include: being lightweight and flexible (allowing component selection based on needs), having low learning curve, strong extensibility (e.g., via third-party extensions like ORM and user authentication), and offering user-friendly documentation. Core concepts encompass routing (mapping URLs to functions with support for dynamic parameters), view functions (handling requests and returning responses), request/response handling (using `request` to fetch data and `response` to deliver content), templates (rendered by Jinja2 for dynamic pages), static files (CSS/JS, etc.), and extension utilities. A basic application example involves writing `app.py` to define routes, render templates, and run the service. It is suitable for starting with small projects and gradually expanding, with recommendations for learning through official documentation and other resources.
Read MorePython Web Development: A Quick Start with the Lightweight Flask Framework
This article introduces the basic content of Flask, a lightweight Python web framework, including: **Definition and Features**: Flask is a lightweight and flexible Python framework that encapsulates repetitive tasks (such as HTTP handling and route management). It has a low learning curve, strong scalability, and is suitable for quickly developing small websites or APIs. **Environment Setup**: Install it via `pip install flask` and verify the version with `flask --version`. **First Application**: Create `app.py` to instantiate Flask, define the root route with `@app.route('/')`, and start the server with `app.run(debug=True)`. Accessing `http://127.0.0.1:5000` will display "Hello, Flask!". **Routes and View Functions**: Support basic routes (e.g., `/about`) and dynamic parameters (e.g., `/user/<username>`). Parameter types include integers, paths, etc. (e.g., `/post/<int:post_id>`). **Templates and Static Files**: Use the Jinja2 template engine for dynamic rendering of variables, loops, and conditions (in the `templates` folder); static resources (CSS/JS) are placed in the `static` folder, accessed via `url_for('static', filename='...')`.
Read More