Django Cheatsheet with Example and Definition

7 October 2023

Django, a high-level Python web framework, simplifies web development with its robust features and clean design. Whether you’re new to Django or a seasoned developer, this Django Cheatsheet will be your trusted companion. It provides clear definitions, practical examples, and tips to help you master Django and build powerful web applications.

Introduction to Django

Django is a Python web framework that promotes rapid development, clean design, and scalability. It comes with built-in features for common web development tasks.

Setting Up Django

Get started with Django:

Installing Django

pip install django

Creating a Django Project

django-admin startproject projectname

Creating Django Apps

Organize your project with Django apps:

App Structure

/projectname
    /appname
        models.py
        views.py
    ...

App Registration

# projectname/settings.py
INSTALLED_APPS = [
    ...
    'appname',
]

Django Models

Define data models with Django:

Defining Models

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.CharField(max_length=100)

Migrations

python manage.py makemigrations
python manage.py migrate

Querying Data

books = Book.objects.all()

Views and Templates

Create dynamic web pages with Django:

Creating Views

from django.http import HttpResponse

def hello(request):
    return HttpResponse("Hello, Django!")

Django Templates

{% extends "base.html" %}
{% block content %}
    <h1>Welcome to My Site</h1>
{% endblock %}

Template Tags

{% for book in books %}
    <li>{{ book.title }}</li>
{% endfor %}

URL Routing

Define URL patterns in Django:

Defining URLs

from django.urls import path

urlpatterns = [
    path('hello/', hello),
]

URL Patterns

path('books/<int:book_id>/', book_detail),

Forms and User Input

Handle user input with Django forms:

Creating Forms

from django import forms

class ContactForm(forms.Form):
    subject = forms.CharField(max_length=100)
    message = forms.CharField(widget=forms.Textarea)

Form Handling

if request.method == 'POST':
    form = ContactForm(request.POST)
    if form.is_valid():
        # process form data

Authentication and Authorization

Manage user authentication and permissions:

User Authentication

from django.contrib.auth import authenticate, login, logout

Permissions and Roles

from django.contrib.auth.decorators import login_required, permission_required

Django Admin

Administer your application with Django’s built-in admin interface:

Admin Interface

from django.contrib import admin

@admin.register(Book)
class BookAdmin(admin.ModelAdmin):
    list_display = ('title', 'author')

Custom Admin Actions

def mark_as_published(modeladmin, request, queryset):
    queryset.update(published=True)

mark_as_published.short_description = "Mark selected books as published"

Middleware and Extensions

Enhance your Django project with middleware and extensions:

Using Middleware

MIDDLEWARE = [
    ...
    'myapp.middleware.MyMiddleware',
]

Django Extensions

pip install django-extensions

Deployment and Production

Prepare your Django project for production:

Preparing for Production

  • Debug mode off
  • Secret key
  • Secure database configuration

Deployment Options

  • Apache
  • Nginx
  • Heroku

Error Handling and Debugging

Handle errors gracefully and debug effectively:

Error Pages

from django.http import HttpResponseNotFound

def error_404(request, exception):
    return HttpResponseNotFound("Page not found")

Debugging Techniques

  • print statements
  • Django Debug Toolbar
  • Logging

Best Practices

Follow best practices for Django development:

Code Organization

/projectname
    /appname
        /templates
        /static
        ...

Security Measures

  • Protect against SQL injection
  • Secure password storage
  • Cross-Site Request Forgery (CSRF) protection

Conclusion

Django empowers developers to create robust web applications efficiently. This cheatsheet equips you with essential Django concepts, from project setup to advanced features like user authentication and deployment. Whether you’re building a simple website or a complex web application, Django’s versatility and reliability make it an excellent choice for web development.