Flask Tutorial

Flask is a lightweight web framework for Python used to build web applications and APIs. It follows a minimal design and provides core features like routing, request handling, and template rendering while allowing developers to add extensions as needed. It is widely used for building small to medium web applications due to its simplicity and flexibility.

Microframework: It is a lightweight web framework with minimal dependencies, giving developers flexibility to design the application structure as needed.
Werkzeug and Jinja2: Flask uses Werkzeug for handling HTTP requests and responses and Jinja2 for creating dynamic HTML templates.
Routing: It provides an easy routing system where URLs are mapped to Python functions using decorators.
Flexible Database Choice: It does not include a built-in ORM, allowing developers to use tools like SQLAlchemy or raw SQL based on project requirements.
API Development: It is widely used for building RESTful APIs and backend services due to its simplicity and modular design.
Development Server: It includes a lightweight development server for running and testing applications locally during development.

Introduction

This section introduces Flask for web development, explains why it is called a micro web framework, compares it with Django and shows how to install Flask on Windows to start building web applications.

Quick Start

Quick introduction to Flask development, covering how to create and run a simple Flask application, understand routes and HTTP methods, work with variable rules, handle redirects and errors and configure the application’s port and host settings.

Templates and Static Files

Flask uses templates to create dynamic web pages with the Jinja2 templating engine. It also covers how static files such as CSS, JavaScript and images are organized and used to style and enhance Flask applications.

Form Handling

This section explains how Flask handles forms, including capturing user input using the request object and managing validation and security with Flask-WTF. It also covers file uploads and CSRF protection.

Configuration

Flask provides configuration support to control application behavior using settings like debug mode, secret keys and environment variables, and allows organizing configurations for development and production environments.

Database

Flask provides support for multiple databases for storing and managing application data. It can work with relational databases like SQLite, PostgreSQL and MySQL using Flask-SQLAlchemy, connect to MongoDB and execute raw SQL queries.

Middlewares

Middlewares in Flask process requests and responses before they reach the application or the client. They are commonly used for tasks such as logging, authentication and modifying requests or responses.

Authentication in Flask is used to verify user identity and manage secure access to applications. It includes login systems, password hashing, session management and permission control.

Rest APIs

Flask makes building REST APIs easy by handling requests like GET, POST, PUT and DELETE. With Flask-RESTful or simple routes, one can send and receive JSON data, manage authentication and secure the API.

Advanced Topics

Flask also supports advanced features for building scalable applications, including asynchronous programming, modular application structure and real-time communication.

Deployment and Error Handling

After development, Flask applications must be deployed and properly handle errors. This section covers deployment methods and techniques for managing application errors.

Projects

This section includes practical Flask projects that demonstrate real-world applications such as portfolio websites, APIs, data visualization and sentiment analysis tools.