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Django for Beginners

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Jason Davies

This document provides an overview of the Django web framework. It discusses Django's mission of encouraging rapid development and clean design. It demonstrates how to create a blog application with Django, including generating models, activating the admin interface, defining URLs and views, and using templates to display data. It also briefly compares Django to other frameworks like Ruby on Rails.

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An Introduction Jason Davies PyCon UK 2007
Django Reinhardt
ljworld.com
 
www.djangoproject.com
 
 
 
Overview of this Tutorial Brief introduction and philosophy Creating Django models The automatic admin interface Views (and URLs) Templates Comparison with other frameworks
Django's Mission Statement “Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design.”
Django Requirements Python (2.3+) PostgreSQL / MySQL / SQLite / ... Apache + mod_python / FastCGI / ...
“Projects” $ django-admin.py startproject myproject
myproject/ __init__.py manage.py settings.py urls.py
$ ./manage.py runserver Validating models... 0 errors found. Django version 0.96-pre, using settings 'myproject.settings' Development server is running at http://127.0.0.1:8000/ Quit the server with CONTROL-C.
 
“Apps” $ django-admin.py startapp blog
myproject/ blog/ __init__.py models.py views.py __init__.py manage.py settings.py urls.py
Creating Models from django.db import models class Blog(models.Model): title = models.CharField(maxlength=200) class Post(models.Model): title = models.CharField(maxlength=200) body = models.TextField() blog = models.ForeignKey(Blog) pub_date = models.DateTimeField()
Activating Models $ ./manage.py syncdb Creating table blog_blog Creating table blog_post Loading 'initial_data' fixtures... No fixtures found.
Activating the Admin Interface from django.db import models class Blog(models.Model): title = models.CharField(maxlength=200) class Admin: list_display = ['title'] class Post(models.Model): title = models.CharField(maxlength=200) body = models.TextField() blog = models.ForeignKey(Blog) pub_date = models.DateTimeField() class Admin: list_display = ['title', 'pub_date']
 
 
Model API $ ./manage.py shell >>> from myproject.blog import Blog >>> b = Blog( ... title=”Jason's Fantastic Blog!!!”) >>> b.save()
>>> all_blogs = Blog.objects.all() >>> print all_blogs [<Blog: Blog object>] >>> print all_blogs.name Jason's Fantastic Blog!!! >>> b = Blog.objects.get(name__contains='Jason') >>> print b.title Jason's Fantastic Blog!!!
URLs ROOT_URLCONF = 'myproject.urls'
URLconfs from django.conf.urls.defaults import * from myproject.blog.views import * urlpatterns = patterns('', (r'^admin/', include('django.contrib.admin.urls')), (r'^blog/$', post_list), (r'^blog/(?P<id>+)/$', post_list), )
Views from django.http import HttpResponse def post_list(request): return HttpReponse(“This is a list of posts!”)
from django.http import HttpResponse from myproject.blog.models import Post def post_list(request): r = “<ul>” posts = Post.objects.order_by(“-pub_date”) for post in posts: r += “<li>%s: %s</li>” % (post.title, post.body) r += “</ul>” return HttpResponse(r) More realistic...
from django.shorcuts import render_to_response from myproject.blog.models import Post def post_list(request): posts = Post.objects.order_by(“-pub_date”) return render_to_response('blog/post_list.html', { 'post_list': posts, }) Better!
from django.shorcuts import render_to_response from myproject.blog.models import Post def post_detail(request, id): post = get_object_or_404(Post, id=id) return render_to_response('blog/post_detail.html', { 'post': post, }) For completeness...
Templates <html> <body> <h1>Jason's Fantastic Blog!!!</h1> <ul> {% for p in post_list %} <li> <a href=”{{ p.id }}/”>{{ p.title|escape }}</a> </li> {% endfor %} </ul> </body> </html>
The magic dot p[“name”] p.name p.name()
Filters {{ var|escape|linebreaks|... }}
base.html <html> <head> <title>{% block title %}{% endblock %} </head> <body> <div id=”content”> {% block content %}{% endblock %} </div> <div id=”footer”> {% block footer %} Copyright Jason Davies 2007. {% endblock %} </div> </body> </html>
{% extends “base.html” %} {% block title %} Posts | {{ block.super }} {% endblock %} {% block content %} <h1>Blog Posts ({{ post_list|length }} total)</h1> <ul> {% for post in post_list %} <li> <a href=”{{ post.id }}/”> {{ post.title|escape }} </a> </li> {% endfor %} </ul> {% endblock %}
Ruby on Rails http://www.rubyonrails.org/
http://www.alrond.com/en/2007/jan/25/performance-test-of-6-leading-frameworks/
Thank you for listening. Jason Davies [email_address] http://www.jasondavies.com/
http://www.mercurytide.co.uk/whitepapers/django-cheat-sheet/
 
 

More Related Content

Django for Beginners

  • 1. An Introduction Jason Davies PyCon UK 2007
  • 4.  
  • 6.  
  • 7.  
  • 8.  
  • 9. Overview of this Tutorial Brief introduction and philosophy Creating Django models The automatic admin interface Views (and URLs) Templates Comparison with other frameworks
  • 10. Django's Mission Statement “Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design.”
  • 11. Django Requirements Python (2.3+) PostgreSQL / MySQL / SQLite / ... Apache + mod_python / FastCGI / ...
  • 12. “Projects” $ django-admin.py startproject myproject
  • 13. myproject/ __init__.py manage.py settings.py urls.py
  • 14. $ ./manage.py runserver Validating models... 0 errors found. Django version 0.96-pre, using settings 'myproject.settings' Development server is running at http://127.0.0.1:8000/ Quit the server with CONTROL-C.
  • 15.  
  • 17. myproject/ blog/ __init__.py models.py views.py __init__.py manage.py settings.py urls.py
  • 18. Creating Models from django.db import models class Blog(models.Model): title = models.CharField(maxlength=200) class Post(models.Model): title = models.CharField(maxlength=200) body = models.TextField() blog = models.ForeignKey(Blog) pub_date = models.DateTimeField()
  • 19. Activating Models $ ./manage.py syncdb Creating table blog_blog Creating table blog_post Loading 'initial_data' fixtures... No fixtures found.
  • 20. Activating the Admin Interface from django.db import models class Blog(models.Model): title = models.CharField(maxlength=200) class Admin: list_display = ['title'] class Post(models.Model): title = models.CharField(maxlength=200) body = models.TextField() blog = models.ForeignKey(Blog) pub_date = models.DateTimeField() class Admin: list_display = ['title', 'pub_date']
  • 21.  
  • 22.  
  • 23. Model API $ ./manage.py shell >>> from myproject.blog import Blog >>> b = Blog( ... title=”Jason's Fantastic Blog!!!”) >>> b.save()
  • 24. >>> all_blogs = Blog.objects.all() >>> print all_blogs [<Blog: Blog object>] >>> print all_blogs.name Jason's Fantastic Blog!!! >>> b = Blog.objects.get(name__contains='Jason') >>> print b.title Jason's Fantastic Blog!!!
  • 25. URLs ROOT_URLCONF = 'myproject.urls'
  • 26. URLconfs from django.conf.urls.defaults import * from myproject.blog.views import * urlpatterns = patterns('', (r'^admin/', include('django.contrib.admin.urls')), (r'^blog/$', post_list), (r'^blog/(?P<id>+)/$', post_list), )
  • 27. Views from django.http import HttpResponse def post_list(request): return HttpReponse(“This is a list of posts!”)
  • 28. from django.http import HttpResponse from myproject.blog.models import Post def post_list(request): r = “<ul>” posts = Post.objects.order_by(“-pub_date”) for post in posts: r += “<li>%s: %s</li>” % (post.title, post.body) r += “</ul>” return HttpResponse(r) More realistic...
  • 29. from django.shorcuts import render_to_response from myproject.blog.models import Post def post_list(request): posts = Post.objects.order_by(“-pub_date”) return render_to_response('blog/post_list.html', { 'post_list': posts, }) Better!
  • 30. from django.shorcuts import render_to_response from myproject.blog.models import Post def post_detail(request, id): post = get_object_or_404(Post, id=id) return render_to_response('blog/post_detail.html', { 'post': post, }) For completeness...
  • 31. Templates <html> <body> <h1>Jason's Fantastic Blog!!!</h1> <ul> {% for p in post_list %} <li> <a href=”{{ p.id }}/”>{{ p.title|escape }}</a> </li> {% endfor %} </ul> </body> </html>
  • 32. The magic dot p[“name”] p.name p.name()
  • 34. base.html <html> <head> <title>{% block title %}{% endblock %} </head> <body> <div id=”content”> {% block content %}{% endblock %} </div> <div id=”footer”> {% block footer %} Copyright Jason Davies 2007. {% endblock %} </div> </body> </html>
  • 35. {% extends “base.html” %} {% block title %} Posts | {{ block.super }} {% endblock %} {% block content %} <h1>Blog Posts ({{ post_list|length }} total)</h1> <ul> {% for post in post_list %} <li> <a href=”{{ post.id }}/”> {{ post.title|escape }} </a> </li> {% endfor %} </ul> {% endblock %}
  • 36. Ruby on Rails http://www.rubyonrails.org/
  • 38. Thank you for listening. Jason Davies [email_address] http://www.jasondavies.com/
  • 40.  
  • 41.  

Editor's Notes

  1. Hello! My name is Jason Davies; I&apos;m a freelance Web developer from Cambridge and I&apos;ve been using Django for about 2 years ever since it was open-sourced in July 2005. Hopefully this will give you a good introduction to the basics of Django. Simon Willison will cover even more stuff in the advanced tutorial.