readme.md

🔑 Flask Login System with SQLite

A beginner-friendly login & signup system using Flask and SQLite.
This project demonstrates:

• ✅ User Signup (create a new account)
• ✅ User Login (check credentials)
• ✅ Session Management (keep users logged in)
• ✅ Cookies (store "last visit" info)
• ✅ "Remember Me" option (stay logged in even after closing browser)

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📂 Project Structure

/project-folder
│── app.py              # Main Flask application
│── users.db            # SQLite database (auto-created)
│── templates/
│    ├── home.html      # Home page (only for logged-in users)
│    ├── login.html     # Login form
│    └── signup.html    # Signup form

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⚡ Installation & Setup

1️⃣ Clone or Download

git clone https://github.com/yourusername/flask-login-system.git
cd flask-login-system

2️⃣ Create Virtual Environment (recommended)

python -m venv venv
source venv/bin/activate   # On Mac/Linux
venv\Scripts\activate      # On Windows

3️⃣ Install Dependencies

pip install flask

4️⃣ Run the App

python app.py

Flask will start at: 👉 http://127.0.0.1:5000/

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🖥️ Usage

1. Open http://127.0.0.1:5000/signup

   • Create a new account.

2. Go to http://127.0.0.1:5000/login

   • Enter username & password.
   • Tick Remember Me if you want to stay logged in after closing browser.

3. After login → you’ll be redirected to Home Page.

   • It will also show your last visit info stored in cookies.

4. To logout → go to http://127.0.0.1:5000/logout.

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🍪 How It Works

• Sessions

  • Store who is logged in (session["username"]).
  • By default, session ends when browser is closed.
  • If "Remember Me" is checked → session lasts 7 days.

• Cookies

  • Store a last_visit message.
  • If "Remember Me" is checked → cookie also lasts 7 days.
  • Otherwise, cookie disappears when browser closes.

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⚠️ Security Notes (for teaching only!)

• Passwords are stored in plain text in this demo (❌ not secure).
• In real applications → always hash passwords using libraries like werkzeug.security or bcrypt.

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✨ Future Improvements

• Add password hashing for security
• Add email verification / password reset
• Use Flask-Login for better authentication management

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👨‍💻 Author

Created as a teaching project for extreme beginners learning Flask, Sessions, and Cookies.

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