Certainly! Here is an article with more detailed instructions and English translations for each step:

Step 1: Setting Up the Environment

Before you begin your project, make sure to set up your development environment. This includes installing necessary software and libraries that will be used throughout the project.

  1. Install Python: Go to the official website (https://www.python.org/downloads/), download the latest version of Python, and install it on your system.
  2. Choose an IDE (Integrated Development Environment): For web development, you might use Visual Studio Code or PyCharm. Choose one based on your preference and experience level.
  3. Set Up Your Project: Create a new directory for your project, navigate into this directory using cd, and initialize a virtual environment with python -m venv myenv. Activate this environment with source myenv/bin/activate.
  4. Install Dependencies: Run pip install flask flask_sqlalchemy pillow numpy matplotlib to install Flask and other required packages.

By following these steps, you'll have a solid foundation to build upon as you work on your project.

Step 2: Planning Your Structure

Once your development environment is set up, you can start planning your structure. This involves deciding on the components and their relationships within your application.

  1. Define Classes: Decide which classes you need in your application. These could include user objects, data models, and service interfaces.
  2. Design Views: Sketch out how different parts of your application should interact with each other. Consider designing a hierarchical structure where views like login forms and dashboard tabs are nested under services.
  3. Plan APIs: Determine what HTTP methods and endpoints are needed to communicate between components. Define routes and URLs for each API endpoint.

Following this plan helps ensure that your application remains modular and maintainable over time.

Step 3: Implementing Database Schema

Now, let's move on to implementing the database schema. This involves creating tables and defining relationships between them.

  1. Create Tables: Use SQL queries to create the tables that represent your application’s entities. For example:

    CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    password_hash VARCHAR(255)
);

    Similarly, define relationships between tables:

    CREATE TABLE sessions (
    session_id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT,
    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id)
);

    Ensure proper indexing and constraints to optimize query performance.

Step 4: Creating Models

After the database schema is defined, you can start writing the models that represent your application's entities.

  1. Model Definition: Write down the definitions for your models, including fields and relationships.
  2. Schema Design: Review the model definitions to understand their structure and relationships. Make sure they align with your design principles.

For instance, if you're working with a simple user model:

class User(models.Model):
    username = models.CharField(max_length=50, unique=True)
    password_hash = models.CharField(max_length=255)
    def __str__(self):
        return self.username

This defines a basic user model with a username field and a hashed password hash.

Step 5: Integrating Services and Controllers

With the models defined, now it's time to integrate services and controllers to handle interactions between components.

  1. Services: Define functions that serve as communication points between different parts of your application.
  2. Controllers: Create controller classes that map requests to actions. These classes define business logic and may involve fetching data from services.
  3. Routing: Use URL routing to map HTTP methods (GET, POST, PUT, DELETE) to specific controller methods.

Here’s an example of a simple controller:

from flask import Blueprint, jsonify
api_bp = Blueprint('api', __name__)
@api_bp.route('/users')
def get_users():
    users = User.query.all()
    return jsonify([user.to_dict() for user in users])

This code maps the /users route to the /api/users endpoint, returning all users as JSON objects.

Step 6: Adding Authentication and Authorization

Finally, add authentication and authorization mechanisms to protect sensitive data.

  1. Authentication: Implement authentication via tokens, cookies, or sessions.
  2. Authorization: Apply access control rules to determine who can access certain resources.
  3. Error Handling: Handle errors gracefully, such as unauthorized access, and provide meaningful error messages.

Example of token-based authentication:

from flask_bcrypt import Bcrypt
bcrypt = Bcrypt()
# Assuming 'auth_token' is a string representing the token
@app.route('/login', methods=['POST'])
def login():
    # Hash the provided token
    auth_token = bcrypt.generate_password_hash(auth_token).decode('utf-8')
    # Store the token in the session
    session['auth_token'] = auth_token
    return jsonify({'message': 'Logged in successfully'}), 200

Using JWT (JSON Web Tokens) for better security:

from jwt import decode
def authenticate(token):
    try:
        payload = decode(token, key=secret_key.encode(), algorithms=["HS256"])
        current_user = User.objects.get(username=payload["username"])
        return current_user
    except Exception as e:
        return None
@app.route('/logout', methods=['DELETE'])
@login_required
def logout():
    session.pop('auth_token', None)
    return jsonify({'message': 'Logged out'})

These steps guide you through the process of setting up your application’s infrastructure, from initial planning to finalizing your applications’ structure and functionality. Each step emphasizes readability and detail, ensuring that every aspect of your project is well-defined and tested.