🐍 Lesson 36: Final Project – Build a Full-Stack Python Web App

Congratulations! You’ve reached Lesson 36, the final lesson of this Python full course. Today we’ll combine everything you’ve learned to build a complete full-stack Python web application.

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💡 Key Benefits of Building a Full-Stack Python Web App

• Build a practical web application from scratch
• Learn to integrate the backend (Flask) with the frontend (HTML, CSS)
• Gain hands-on experience with SQLAlchemy and database management
• Develop real-world skills for your web development portfolio

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📌 Project Overview

We will build a To-Do List Web App with the following features:

• ✅ User authentication (login/logout)
• 📄 Add, view, update, and delete tasks
• 📦 Database integration using SQLAlchemy
• 🌐 Dynamic HTML templates with Jinja2
• 🔒 Session management

📂 Project Structure

project/
│── app.py
│── templates/
│   ├── login.html
│   ├── dashboard.html
│   └── task_form.html

📦 1. Setting Up Flask & SQLAlchemy

from flask import Flask, render_template, request, redirect, url_for, session
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.secret_key = "your_secret_key"
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///tasks.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(50), unique=True, nullable=False)
    password = db.Column(db.String(50), nullable=False)

class Task(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(100), nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)

with app.app_context():
    db.create_all()

📄 2. User Authentication Routes

@app.route("/login", methods=["GET","POST"])
def login():
    if request.method == "POST":
        username = request.form["username"]
        password = request.form["password"]
        user = User.query.filter_by(username=username, password=password).first()
        if user:
            session["user_id"] = user.id
            return redirect(url_for("dashboard"))
        else:
            return "Invalid credentials"
    return render_template("login.html")

@app.route("/logout")
def logout():
    session.pop("user_id", None)
    return redirect(url_for("login"))

📦 3. Dashboard & Task Management

@app.route("/dashboard")
def dashboard():
    if "user_id" in session:
        tasks = Task.query.filter_by(user_id=session["user_id"]).all()
        return render_template("dashboard.html", tasks=tasks)
    return redirect(url_for("login"))

@app.route("/add_task", methods=["GET","POST"])
def add_task():
    if "user_id" in session:
        if request.method == "POST":
            title = request.form["title"]
            task = Task(title=title, user_id=session["user_id"])
            db.session.add(task)
            db.session.commit()
            return redirect(url_for("dashboard"))
        return render_template("task_form.html")
    return redirect(url_for("login"))

@app.route("/delete_task/")
def delete_task(id):
    task = Task.query.get_or_404(id)
    db.session.delete(task)
    db.session.commit()
    return redirect(url_for("dashboard"))

📂 4. Templates Overview

• login.html → Login form
• dashboard.html → List of tasks + links to add/delete
• task_form.html → Form to add a new task

🧠 Why This Project Is Important

• Combines backend, frontend, and database
• Introduces real full-stack workflow
• Strengthens Python, Flask, HTML, and database skills
• Perfect project to showcase in your portfolio

❓ Frequently Asked Questions (FAQ)

1. What is SQLAlchemy, and why is it useful in Flask?

SQLAlchemy is an Object Relational Mapper (ORM) for Python, allowing you to interact with databases using Python objects. It helps map Python classes to database tables, making database interactions smoother and easier to manage.

2. How do I manage user authentication securely in Flask?

To securely manage user authentication, you should hash passwords using libraries like werkzeug.security before storing them in the database. Always use HTTPS for secure communication.

3. What is the secret_key used for in Flask sessions?

Flask’s secret_key is used to sign session cookies. This ensures that the session data cannot be tampered with by clients. It should be a random and secure value.

4. Can I deploy this project to production?

Yes! You can deploy your Flask app to platforms like Heroku or PythonAnywhere. Ensure you use environment variables for sensitive information (like the secret_key) and follow platform-specific deployment instructions.

5. Can I integrate more features in this To-Do List App?

Absolutely! You can add task priority, task due dates, reminders, user profile pages, or even use APIs to sync tasks with other platforms like Google Calendar or Todoist.

🧪 Practice & Enhancements

1. Add task completion status (done/undone)
2. Add a user registration page
3. Add Bootstrap styling for a modern look
4. Add due dates for tasks and sorting
5. Deploy your app using Heroku or PythonAnywhere

🎉 Congratulations!

You have completed the full Python course, covering everything from beginner basics to advanced full-stack development!