Essential for Tech Newbies: Complete Guide to Setting Up a Flask Development Environment
This article introduces the basics of Flask, a lightweight Python Web framework, suitable for beginners to get started quickly. It first clarifies that Flask is as flexible as building with blocks, allowing the development of simple websites without complex configurations. The core steps include: 1. **Preparing the Python environment**: Download the 3.x version (e.g., 3.9+) from the official website. When installing on Windows, check "Add Python to PATH". Verify with `python --version`. 2. **Installing Flask**: Use `pip install flask` (or a domestic mirror for acceleration) and verify with `flask --version`. 3. **Virtual environment (optional but recommended)**: Create an isolated project dependency environment by running `python -m venv venv`. Activate it with `venv\Scripts\activate` on Windows or `source venv/bin/activate` on Mac/Linux. 4. **First application**: Create `app.py`, import Flask and create an instance, define a route `@app.route('/')` to return content, run `python app.py`, and visit `http://127.0.0.1:5000/` in the browser to see the result. The article also mentions common issues (such as installation failures and port conflicts) and troubleshooting approaches, encouraging...
Read MoreFlask and Frontend Interaction: AJAX Requests and JSON Responses
This article introduces the method of implementing front-end and back-end data interaction in Flask using AJAX and JSON. In a front-end and back-end separated architecture, the front-end is responsible for interface interaction, while the back-end handles business logic. AJAX enables asynchronous requests, and JSON serves as the data exchange format. The core process is: front-end initiates an asynchronous request → back-end processes and returns JSON → front-end parses and renders the data. Practical example: Create `app.py` in Flask, where the `/` route renders the front-end page, and the `/api/get_data` route returns simulated JSON data (including status, message, and a list). The front-end uses `fetch` to asynchronously request `/api/get_data`, and updates the page after obtaining the data. Key knowledge points include: using `jsonify` on the back-end to return JSON, using `async/await` on the front-end to simplify asynchronous code, supporting GET/POST requests and data transfer (e.g., `request.get_json()` to receive front-end data). The core steps are clear, and it can be extended to scenarios such as form submission and database interaction.
Read MoreFlask Session Management: Basic Applications of Cookies and Sessions
This article introduces two core methods of session management in Flask and their applications. Session management enables websites to "remember" user states (such as login information), which Flask implements through Cookies and Sessions. Cookies are small data (approximately 4KB) stored on the client side (browser), suitable for non-sensitive temporary information (e.g., usernames, theme settings). They can be set using `response.set_cookie()` and read with `request.cookies.get()`, but users can disable them, and they are not suitable for sensitive information. Sessions are stored on the server side, offering higher security and suitable for sensitive data (e.g., user IDs). A `secret_key` must first be set for encryption, and they are stored/retrieved via the `session` object, with clearing done using `pop()` or `clear()`. By default, they use in-memory storage, which is lost upon server restart; Redis persistence is recommended for production environments. Comparison: Cookies are lightweight and simple but less secure, while Sessions are secure and reliable but increase server pressure. In actual development, they are often used in combination: Cookies store the Session ID, and Sessions store core user states.
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