Hands On Session on Django

Jul 16, 2016From

This session

Architecture

Displaying static html pages

Template Language

Django models

ORM

Django

What is Django?

● A Python Framework: designed to support the development of dynamic websites

Sites Built With Django

Why Django?

● ORM

● Built In Admin Interface

● Internationalization.

● Reusability

●Django takes care of user authentication, content administration, sitemaps, RSS feeds, and many more tasks

●Testing Libraries.

●Community of 10796 people, 161 countries, 3180 packages and projects.

●It’s open source.

Architecture.

Browser(Request/Response)

URLS

Views

Templates

Models

Database

Django Installation

$ sudo apt-get install python-setuptools python-dev build-

essential tree

$ sudo apt-get install python-pip python-virtualenv

$ virtualenv <env-name>

$ source <env-name>/bin/activate

$ pip install django

Start New Project!

$ django-admin.py startproject <your-project-name>

$ cd <project-name>

$ tree

$ python manage.py runserver

$ python manage.py startapp <app-name>

$ tree <app-name>

$ python manage.py migrate

Setting.py

● SECRET_KEY● INSTALLED_APPS● DATABASES● TEMPLATES● STATIC_URL● AUTH_PASSWORD_VALIDATORS● TEMPLATE_CONTEXT_PROCESSORS● MIDDLEWARE_CLASSES● YOUR_NEW_SETTINGS # You can add new settings

Your First view

=> blog/views.py

from django.http import HttpResponse

def greetings(request):

return HttpResponse("GooD Morning")

=> blog/urls.py

from django.conf.urls import url

from blog.views import greetings

urlpatterns = [

url(r'^greetings/$', greetings, name='greetings'),

]

Rendering html codeblog/views.py

from django.shortcuts import render_to_response

def aboutme(request):

name = "MicroPyramid"

age = 5

return render_to_response('aboutme.html', {

'name': name,

'age': age

})

templates/aboutme.html

<h1>About Me</h1>

<p>my name: {{name}}</p>

<p>age: {{age}}</p>

Models.py

blog/models.py

from django.db import models

from datetime import datetime

class Post(models.Model):

title = models.CharField(max_length=200)

description = models.TextField()

createddate = models.DateTimeField(default=datetime.now())

$ python manage.py makemigrations blog

$ python manage.py migrate blog

ORM: Creating data

# Creating new rows with Orm

>>> python manage.py shell

>>> from blog.models import Post

>>> p = Post()

>>> p.title = "learn some math"

>>> p.description = "1+2 = 3"

>>> p.save()

or

>>> Post.objects.create(title="Learn some science", description="E = mc2")

<Post: Post object>

ORM: Reading data

# Reading data from database with ORM

>>> Post.objects.all()

>>> Post.objects.all().count()

>>> for p in Post.objects.all():

... print(p.id)

... print(p.title)

... print(p.description)

ORM: Editing Data

>>> p = Post.objects.get(title="learn some math")

>>> p.title = "Math is Interesting"

>>> p.description = "a2+2ab+b2"

>>> p.save()

>>> p = Post.objects.get(title="Learn some science")

>>> p.delete()

>>> Post.objects.count()

Rendering data from database

blog/views.py

def blog_list(request):

post_list = Post.objects.all()

return render_to_response('postlist.html', {

'post_list': post_list

})

postlist.html

<h1>All Blog Posts</h1>

{% for post in post_list %}

<h3>{{post.title}}</h3>

<p>{{post.description}}</p>

{% endfor %}

Another Example

def blog_detail(request, post_id):

post = Post.objects.get(id=post_id)

return render_to_response('postdetail.html', {

'post': post

})

blog/urls.py

url(r'^blog-detail/(?P<post_id>\d+)$', blog_detail, name='blog_list'),

detail.html

<h1>{{post.title}}</h1>

<p>{{post.createddate}}</p>

<p>{{post.description}}</p>

Questions?