Introduction to Django

Django

"""The Web framework for perfectionists with deadlines."""

"""Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design."""

https://www.djangoproject.com/

What is inside?

● Built-in ORM(Object-relational Mapper)

● Simple but powerful URL system

● Built-in template system

● I10n(Internationalization)

● Cache system

● Built-in authentication system

● Built-in webserver(for development)

● Automatic admin interface

MVT not MVC

● Model○ defines the data structure○ takes care for querying the database

● View○ defines what data should be presented○ returns HTTP response

● Template○ renders the data in suitable format - HTML/XML/etc.

The live of request

Project structureTo start new project run:

django-admin.py startproject my_projectThe following structure will be created

my_project/ manage.py my_project/ __init__.py settings.py # project settings reside here urls.py wsgi.py

This is the default created and good for learning the basics but this way the settings may be hard to maintain for project in production. Alternative approach is available at http://ilian.i-n-i.org/django-project-file-structure/.

Application structureTo create new application in you project just run the following command in the shell:

python manage.py startapp appThe following structure will be created

app/ __init__.py admin.py # not created automatically before 1.5 models.py tests.py views.py

There is no urls.py file but most developer find it useful to keep the application specific URLs inside it and include them in the main URLs configuration file.

Models# models.pyfrom django.db import modelsfrom django.utils.translation import ugettext_lazy as _

class News(models.Model): title = models.CharField(_('Title'), max_length=255) slug = models.SlugField(_('Slug')) content = models.TextField()

To create the tables for the define models just run:python manage.py syncdb

URLs dispatcher# urls.pyfrom django.conf.urls import patterns, url, include

urlpatterns = patterns('', url(r'^$', 'app.home', name='home'), # give the specific URL meaningful name url(r'offers/', include('offers.urls')), # include URLs from another app (r'^news/$', 'news.views.offers'), # point to specific view (r'^news/(\d{4})/$', 'news.views.year_archive'), # pass arg(s) (r'^news/(\d{4})/(\d{2})/$', 'news.views.month_archive'), # pass arg(s) (r'^news/(?P<slug>[-\w]+)/$', 'news.views.single_news'), # pass named args)

● URLs dispatcher uses regular expression● The first match found is called● All arguments are passed as unicode strings

Views# views.pyfrom .models import Newsfrom django.shortcuts import get_object_or_404

def single_news(request, slug): news = get_object_or_404(News.objects.public(), slug=slug) return render_to_response('news/single_news.html', {'news': news})

Templates# template.html

{% extends 'my_project/base.html' %}

<h1>{{ news.title }}</h1><div class="news-content">

{{ news.content|safe }}</div>

About Me

eng. Ilian Iliev

● Web Developer for 9+ years

● Python/Django fan for 3+ years

● ilian@i-n-i.org

● http://ilian.i-n-i.org

● https://github.com/IlianIliev/