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)  

---

## 📂 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
```bash
git clone https://github.com/yourusername/flask-login-system.git
cd flask-login-system
````

### 2️⃣ Create Virtual Environment (recommended)

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

### 3️⃣ Install Dependencies

```bash
pip install flask
```

### 4️⃣ Run the App

```bash
python app.py
```

Flask will start at:
👉 [http://127.0.0.1:5000/](http://127.0.0.1:5000/)

---

## 🖥️ 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`.

---

## 🍪 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

---

## 👨‍💻 Author

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


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