django

1. What is Django?

Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It takes care of much of the hassle of web development, enabling developers to focus on writing their application instead of reinventing the wheel.

2. Setting Up Your Environment

To set up Django, install it via pip. Ensure you have Python installed on your system.

pip install django

Verify the installation by running the following command:

django-admin --version

3. Your First Django Project

Create a new Django project with the following command:

django-admin startproject myproject

Navigate into the project directory and start the development server:

cd myproject
python manage.py runserver

Visit http://127.0.0.1:8000/ to see your project in action.

4. Django Models

Models in Django define the structure of your database. You can create models by creating Python classes that inherit from django.db.models.Model.

from django.db import models

class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.title

After defining the model, run the migration commands to create the corresponding table in the database:

python manage.py makemigrations
python manage.py migrate

5. Django Views

Views in Django are functions that handle requests and return responses. They can render templates, return JSON, or redirect to other views.

from django.http import HttpResponse
from django.shortcuts import render

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

Views can also be linked to templates for dynamic content rendering.

6. URL Routing

In Django, URLs are mapped to views through a URL configuration file called urls.py. This file defines the URL patterns for the project or app.

from django.urls import path
from . import views

urlpatterns = [
    path('', views.home, name='home'),
    path('about/', views.about, name='about'),
]

Include the app’s urls.py in the main project’s urls.py:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('myapp.urls')),
]

7. Templates

Templates in Django allow you to generate HTML dynamically. Django uses the Jinja2 template engine by default.

# Example:
# In the view function:
def home(request):
    return render(request, 'home.html')

# In the template (home.html):
Welcome to Django!

8. Forms

Forms in Django are used to handle user input and validate it. You can define forms using Django’s form classes.

from django import forms

class PostForm(forms.Form):
    title = forms.CharField(max_length=100)
    content = forms.CharField(widget=forms.Textarea)

# In the view:
def post_create(request):
    if request.method == 'POST':
        form = PostForm(request.POST)
        if form.is_valid():
            # Process form data
            pass
    else:
        form = PostForm()
    return render(request, 'post_create.html', {'form': form})

9. Static Files

Static files (CSS, JavaScript, images) are stored in a directory named static. You can refer to them in your templates using the static template tag.

{% load static %}

10. Django Admin

Django comes with a powerful admin interface that allows you to manage your database records. To use the admin interface, register your models in admin.py.

from django.contrib import admin
from .models import Post

admin.site.register(Post)

Then, create a superuser to access the admin interface:

python manage.py createsuperuser

Once the superuser is created, access the admin interface at http://127.0.0.1:8000/admin/.