# ♻️ Day 8: Reusability & Best Practices – Beginner’s Web Dev Series Welcome to **Day 8** of our Django journey! By now, you’ve built working views, forms, authentication flows, and templates. Today, you’ll learn how to **keep your code clean, reusable, and production-ready** using the DRY principle, environment variables, and Git for version control. --- ## 📍 What You’ll Learn 1. The **DRY Principle** in Django (Don’t Repeat Yourself) 2. How to use reusable **models**, **views**, and **templates** 3. Why and how to use **environment variables** 4. How to set up **Git and GitHub** 5. Adding a `.gitignore` file 6. Creating and using `.env` and `.env.example` --- ## 🔁 1. The DRY Principle in Django > **DRY** = Don't Repeat Yourself > Reusability = Avoid writing the same thing multiple times. ### ✅ In Models Instead of repeating timestamp fields in every model: ```python class BaseTimestampModel(models.Model): created_at = models.DateTimeField(auto_now_add=True) updated_at = models.DateTimeField(auto_now=True) class Meta: abstract = True ``` Then reuse: ```python class Post(BaseTimestampModel): title = models.CharField(max_length=200) ``` --- ### ✅ In Templates Use **template inheritance**: ```html {% block head %}{% endblock %} {% block content %}{% endblock %} ``` ```html {% extends 'base.html' %} {% block content %}

Welcome!

{% endblock %} ``` --- ## 🔐 2. Environment Variables Don't hardcode secrets like this: ```python SECRET_KEY = 'abc123' ❌ ``` Use a `.env` file: ```bash # .env SECRET_KEY=mysecretkey DEBUG=True ``` Load it using `python-decouple` or `django-environ`. ### Install: ```bash pip install python-decouple ``` ### Update [`settings.py`](http://settings.py): ```python from decouple import config SECRET_KEY = config('SECRET_KEY') DEBUG = config('DEBUG', cast=bool) ``` --- ## 🗂️ 3. Git & GitHub Setup ### ✅ Initialize Git ```bash git init git add . git commit -m "Initial commit" ``` ### ✅ Push to GitHub ```bash gh repo create myproject --public git push -u origin main ``` --- ## 🛑 4. Add `.gitignore` Create `.gitignore` in your root directory: ```txt # .gitignore *.pyc __pycache__/ env/ venv/ db.sqlite3 *.env /static/ /media/ ``` > ✅ This prevents sensitive and unnecessary files from being tracked by Git. --- ## 📂 5. Create `.env.example` ```css # .env.example DEBUG=True SECRET_KEY=your-secret-key-here ``` > ✅ Helps teammates or future you understand what env vars are needed. --- ## ✅ Task for Day 8 * Refactor a model using mixins (e.g., timestamps) * Setup a `.env` file using `python-decouple` * Add `.gitignore` and push project to GitHub * Create a `.env.example` file for sharing --- ## 🚀 Coming Up: Day 9 – REST API In **Day 9**, we’ll cover: * Creating serializers * Creating API Views * Managing json payloads ---