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1. What is Django
2. What is Python
3. Django’s Capabilities
a. All-in-One and Ready to Use
b. Modularity
c. Pattern: MTV and DRY
d. Deployment strategies
4. Useful Links
Summary
› Django is a high-level Python Web framework.
› Rapid development and clean, pragmatic design.
› Focus on writing your app without needing to
reinvent the wheel.
› It’s free and open source.
From https://www.djangoproject.com/
What is Django ?
Instagram: http://instagram.com/
Pinterest: https://www.pinterest.com/
The Washington Post:
http://www.washingtonpost.com/
Mozilla’s blog:
http://blog.mozilla.org/webdev/
My blog! http://blog.itsmurfs.it/
Who use Django ?
Enterprise Point Of View
Free and Open-source.
Thousand of free reusable apps already pluggable
into one’s project.
Compatible with all the main databases.
Compatible with all the JS and CSS Frameworks.
Why Django ?
Developer Point Of View
Use and learn a new language: Python.
DB Management and ORM built-in.
Rich documentation.
Active community.
Modular architecture.
DRY Principle (Don’t Repeat Yourself).
MVC Pattern reinterpreted in MTV.
Why DJAngo ?
Questions?
What is Django ?
Python is an interpreted, interactive, object-oriented
programming language.
Platform indipendent.
Combines remarkable power with very clear syntax.
Very rich community and many libraries and
frameworks.
It’s free and open source.
What is python ?
Open google and search for: most used programming
languages 2014
Who use Python?
Syntax:
No “;” and “{ }”
Blocks starts with “:” and are identified by Indentation
No statically typed. You don’t need to declare any variable
You can mix object-oriented and imperative programming.
What is python ?
What is python ?
What is python ?
List:
Declared using “[ ]”
Access using index
Mutable
Tuple:
Declared using “( )”
Access using index
Immutable Dictionary:
Declared using “ { } “ Access using keyword
Data Structure:
What is python ?
Easy to install:
Download and Install Python:
https://www.python.org/downloads/
Install pip ( https://bootstrap.pypa.io/get-pip.py ):
Install Django
Django’s Capabilities
python get-pip.py
pip install django
› Don’t worry there is an IDE that can do these dirties things for you:
› Or you can use Eclipse with pyDev (http://pydev.org/ )
› Ready to use:
To start a new project just type in a cmd:
Then starts a new app with:
Django’s Capabilities
django-admin.py startproject mysite
python manage.py startapp polls
Let’s look at the structure the commands have
created:
Django’s Capabilities
Project root
Project package
App package
Project configurations files
Application files
All in one:› With these two commands we have:
Created the project structure
Installed the ORM
Installed a development server
Installed and configured an SQLite database
Installed the admin interface
Installed a ready to use unit-test environement
Django’s Capabilities
– Create the database tables based on the models found in the installed apps.
– Create the database for the authentication system included in django
– Create a superuser account for the authentication system
– Set up a system for propagating change makes to the models into the database
schema
python manage.py migrate
Modularity: You can take existing Python packages or Django apps and compose
them into your own web project. You only need to write the parts that
make your project unique.
Built-in reusable apps:
django.contrib.admin – The admin site.
django.contrib.auth – An authentication system.
django.contrib.contenttypes – A framework for content types.
django.contrib.sessions – A session framework.
django.contrib.messages – A messaging framework.
django.contrib.staticfiles – A framework for managing static files.
Django’s Capabilities
Third party reusable apps: Django REST framework is a framework to build REST APIs.
Celery is the standard to manage asynchronous, distributed job queues.
Django mailer provides a backend for sending email
django-allauth allows for both local and social authentication
django-grappelli A jazzy skin for the Django Admin-Interface
django-tables2 An app for creating HTML tables
django-dajax Easy to use library to create asynchronous presentation logic with django
And much more….
Django’s Capabilities
› All these apps can be installed simply typing:
pip install <app_name>
How to write reusable apps:
The app we have just created is already reusable!
Just copy and paste it to another project and link it in the settings.py
Of course there is a more complete way to package an app:
https://docs.djangoproject.com/en/1.7/intro/reusable-apps/#packaging-yo
ur-app
How to find more apps:
Check https://www.djangopackages.com/ a directory of reusable apps, sites,
tools, and more for your Django projects
Ask to the community: https://groups.google.com/forum/#!forum/django-it
Try to search them: www.google.com
Django’s Capabilities
DRY (Don’t Repeat Yourself)
The DRY principal was one of the fundamental concepts that Django was designed around.
The DRY principal is all about keeping code simple and non repeating. This allows developers to reuse code they wrote for one project in another project.
To help developers adhere to the DRY principle, Django forces users to use the MVC by initially creating a standard project structure.
Django’s Capabilities
A different interpretation of the MVC: MTV: Model View Template
In django interpretation of MVC, the “view” describes the data that gets presented to the user. It’s not necessarily how the data looks, but which data is presented. The view describes which data you see, not how you see it.
Furthermore, it’s sensible to separate content from presentation – which is where templates come in. In Django, a “view” describes which data is presented, but a view normally delegates to a template, which describes how the data is presented.
Django’s Capabilities
Deployment Strategies:
In the cloud:
Heroku
Google Appengine
On a remote machine:
NGINX + uWSGI or Gunicorn
Apache + mod_wsgi
Django’s Capabilities
Official site: https://www.djangoproject.com/
Official google groups:
https://groups.google.com/forum/#!forum/django-users
Italian community: https://groups.google.com/forum/#!forum/django-it
Snippets of reusable code: https://djangosnippets.org/
Collection of useful links: http://www.fullstackpython.com/django.html
Useful links
› Learning sites:
– https://docs.djangoproject.com/en/1.7/intro/
– http://www.tangowithdjango.com/
– http://tutorial.djangogirls.org/en/index.html
– http://effectivedjango.com/tutorial/
– http://www.djangobook.com/en/2.0/index.html
– http://stacktrace.it/site_media/luambo/uploads/2009/09/14/Copia_visione_Django.pdf
Questions?
Thanks.
