Django Framework Introduction

Apresentando

Marcel P. Caraciolo
@marcelcaraciolo

Residência RISE - 2011

Saturday, May 21, 2011

O que é Django ?

Residência de Reuso - 2011.1 - Recife/PE


Não é Jungle. É Django.

O que é Django ?


Não é Django Reinhardt ... na verdade é

É um framework web

Criado em 2005 Aplicação Web

Lawrence, Kansas -
Lawerence Journal World

Licença BSD



É um framework web

Criado em 2005 DRY Aplicação Web

Lawrence, Kansas - Repeat Yourself
Don’t
Lawerence Journal World

Licença BSD

http://www.ﬂickr.com/photos/plinton/215437652/

Django é Python!
!"#$%&'()*"*
! *+"(,%-'./0.
Escrito em Python
!"#$$$%&'(&)*+,
Focado em
Desenvolvimento Ágil

Don’t Repeat yourself


Projeto == Várias aplicações

django.contrib.admin django-registration

south django.contrib.comments

django-mailer django-pagination

...
http://djangopackages.com


E isto é MVC ?

Models

Controllers Views



Alguns chamam de MTV



Alguns chamam de MTV

Model - Template - Views

Aplicações

Deve fazer uma coisa, e fazer direito

Se a descrição de sua aplicação for maior que uma
linha, talvez ela precise ser quebrada

Reutilizável (DRY se lembra ?)

Talvez já exista!



Aplicações
Instalando a aplicação
Coloque no path (PYTHONPATH)

Coloque no INSTALLED_APPS no settings.py

settings.py



Aplicações

A aplicação é auto-contida
tests.py
urls.py
templates/
admin.py



Fácil de Usar

$ pip install django
$ django-admin.py startproject dwitter



Fácil de Usar
!"#$"%&'#()"*%+"*,#-)* 6#%7%8-9#"*(%:;<

$ pip install django

__init__.py
manage.py
settings.py
urls.py

!"#$%&'"(%")*"+,'-(.&'///"0"%%./%*(%0#%1/%2#3#444 de Reuso - 2011.1 - Recife/PE
Residência

Saturday, May 21, 2011 !".51"23%+'*(4'%"2(")*"+,'-(.&'"5!"#$%&#'(6"(*"278*9'/

Fácil de Usar

$ cd dwitter
!""#$%#"&$'()*"+&,"+-(%*+
$ python manage.py runserver
.(&/&0%1("+)&234

$ cd dwitter

Validating models...
0 errors found

Django version 1.1, using settings 'dwitter.settings'
Development server is running at http://
127.0.0.1:8000/
Quit the server with CONTROL-C.

Já vem com um servidor web ! Residência de Reuso - 2011.1 - Recife/PE


Fácil de Usar



!"#$%&'#()'*+)&,-.
Quem usa ?

!"#$$$ Residência de Reuso - 2011.1 - Recife/PE


Documentação


Banco de Dados

!"#$%

Banco!"#$%&'()*+
de Dados

def book_list(request):
try:
db = MySQLdb.connect(user='me', db='mydb',
passwd='secret', host='localhost')
cursor = db.cursor()
cursor.execute('SELECT nama FROM books ORDER BY name')
names = []
for row in cursor.fetchall()
names.append(row[0])
db.close()
except:
return render_to_response('500.html')
return render_to_response('book_list.html', {'names':names})



Banco de Dados

12 linhas em Python ... :(


Banco de Dados

12 linhas em Python ... :(
!"#$%!&'()*+"(,-./0-,$1-223045

ORM
Padrão Active Record

!"#$%&'()*+
Classe Table

def book_list(request):

names = Books.objects.all().order_by('name')

return render_to_response('book_list.html', {'names':names})



Criar tabelas?! Fácil!

$ python manage.py syncdb
Crie as tabelas no banco. E pronto!


Vamos começar ?

djangoproject.com - site oﬁcial
djangobrasil.org - site oﬁcial nacional
djangogigs.com - vagas de empregro
djangopeople.net - rede social
djangosites.org - rede social de sites em django
djangosearch.com - busca assuntos relacionados
djangocodesearch.com - busca nos fontes


Vamos à prática!



!"#$%&'()(*+,%#-.'/0%
Instalação Python

$ sudo apt-get install python
$ sudo apt-get install python
sudo apt-get install python

http://www.python.org/download
http://www.python.org/download/
http://www.python.org/download/

Já vem com python instalado
!"#$%&'#()*+%,"-./0'%.)1%2'*1,#"'1%2.5.4%0%2.6.1
!"#$%&'#()*+%,"-./0'%.)1%2'*1,#"'1%2.5.4%0%2.6.1


2)3$45(6-/1) 2)!"*&#5,(,1)
Instalação de Banco de Dados
2)7"/+%'-89: 2)8<=(/-)89:)>#<?@-'-
2);<89: 2)A.;)0.B
2);54'"/"C)89:)8-'D-')BEEF
2)3'(46-
Poderíamos escolher dentre vários SGBD’s
2)G5'-=5',
2)!"#$%& 2)30.!



Instalação de Banco de Dados

Vamos usar o Sqlite!

Precisa instalar ?! Não :D

Python já vem com SGBD incluso!

http://docs.python.org/library/sqlite3.html



Instalação de Django
3 maneiras!

apt-get install python-django

http://www.djangoproject.com/download
python setup.py install

http://www.djangoproject.com/svn/django/trunk



!""#$%&'()
!""#$%&'()
!""#$%&'()
Instalação de Django

>>> import django
>>> import django
>>> import django
>>> django.VERSION
>>> django.VERSION
>>> django.VERSION
>>> import 'final', 0)
(1, 1, 0, django
>>> django.VERSION 0)
(1, 1, 0, 'final',
(1, 1, 0, 'final', 0)
(1, 1, 0, 'final', 0)

>>> import django
>>> import(most recent call last):
>>> import django
Traceback
django
>>> import (most recent 1, inlast):
Traceback django call
Traceback (most recent call last):
File "<stdin>", line <module>
File "<stdin>", line 1, in last):
"<stdin>", line call <module>
1, in <module>
Traceback (most recent named django
File
ImportError: No module
ImportError: No module 1, in <module>
File "<stdin>", line named django
ImportError: No module named django
ImportError: No module named django



!"#$"%&'#()"*%+"*,#-)*
Criando um projeto 5#%6%7-8#"*(%9:;

$ django-admin.py startproject seminario

__init__.py
manage.py
settings.py
urls.py

!"#$%&'"(%")*"+,'-(.&'///"0"%%./%*(%0#%1/%2#3#444



Criando um projeto

!"#$%!&'( Residência de Reuso - 2011.1 - Recife/PE


!""#$%#"&$'()*"+&,"+-(%*+
Criando um projeto
.(&/&0%1("+)&234

$ cd dwitter

Validating models...
0 errors found

Django version 1.1, using settings 'dwitter.settings'
Development server is running at http://
127.0.0.1:8000/
Quit the server with CONTROL-C.



!"#$%&$'()&*+
Entendendo sua App

!!"#$!%&%!+,%- "'()*%&%.%/0-)1% #!+),!$*"!,%&%234-"5%6



!"#$%&%'($)*$
urls.py
! "#$%&'()*$+,-$./&$+&,-+$&*.*$/0(),+$1($(2,)+1+$/+)+$#+3$
/(4&5*2(3$6778
Módulo urls.py serve como porta de entrada para requisições HTTP

! As URL’s são deﬁnidas por expressões regulares que redirecionam as
9($1(%2(2$:;<3$(#(=+2,(3$.(15+2,($(>/)(35*2(3$)(=0#+)(3$
requisições para as respectivas views
?0($)(15)5=(2$+$@02&5*2(3$1($0(12$./&

'E/FGG.B35,(A&*.G+H*0,G 0)#3A/B
I0)#/+E()23J

',.# C5(D3A/B ...



!"#$%&%'($)*$
views.py
! "#$%&'()*'$+,$-),./012$3,()4,$(565$1#376,835/$&'$549,85$
Módulo views.py tem funções com parâmetros um objeto HttpRequest
+,-"./0.$)$2$85+5/$:5/$1#376,835/$+,$:#$;<"$(#18&3#+5/=$
Retorna um objeto HttpResponse
8,'),'+5$>&,$+,-5:-,3$/),613,$&'$549,85$+,-".$-12$.

+,-"./0.$)345%666

-),./012
+,-".$-12$.34



!"#$%&%'($)*$
Exemplo!"#$%&%'($)*$
+,-./01%2!""http://mysite.com/time
+,-./01%2!""http://mysite.com/time
http://mysite.com.time
from django.conf.urls.defaults import * *
from django.conf.urls.defaults import
from mysite.views import hora_actual
from mysite.views import hora_actual
!"#$%&' urlpatterns
!"#$%&' urlpatterns =
urls.py = patterns('',
patterns('',
(r'^time/$', hora_actual),
)(r'^time/$', hora_actual),
)

from django.http import HttpResponse
from datetime import datetime
()*+$%&' def hora_actual(request):
now = datetime.now()
()*+$%&'
views.py def hora_actual(request):% now
html = "Son las %s."
= datetime.now()
nowreturn HttpResponse(html)
html = "Son las %s." % now
return HttpResponse(html)



!"#$%&%'($)*$
Exemplo 2
+,-./01%2!""http://mysite.com/time/plus/2
+,-./01%2!""http://mysite.com/time/plus/2
http://mysite.com.time/plus/2
from django.conf.urls.defaults import *
from django.conf.urls.defaults import *
from mysite.views import dentro_de
from mysite.views import dentro_de
urls.py
!"#$%&'
!"#$%&' urlpatterns = patterns('',
urlpatterns = patterns('',
(r'^time/plus/(d{1,2})/$', dentro_de),
(r'^time/plus/(d{1,2})/$', dentro_de),
)
)

from datetime import datetime, timedelta
from datetime import datetime, timedelta
def dentro_de(request, offset):
views.py
()*+$%&'
()*+$%&'
def offset = int(offset)
dentro_de(request, offset):
offset = int(offset)
dt = datetime.now() + timedelta(hours=offset)
dt = datetime.now() + serán las %s." % (offset, dt)
html = "En %i hora(s), timedelta(hours=offset)
html = "En %i hora(s), serán las %s." % (offset, dt)



Html dentro da views?


!"#$%&'"(
Templates
! "#$%&%'()%()*+,-%(.#($)"("*'&+,-*(%(/'%(-%$%(,'.#$#'.,#'0#1
Separa a camada de apresentação de forma independente
! 2,-3#&45(,'.#$#'.,#'0#5(61307)8
! Linguagem de marcação embarcada dentro do html (Designers :D)
9#'+/%:#(,'.#$#'.,#'0#(6;$%&%(.,5#<%.4&#5=8



!"#$%&'"(
Templates
! "#$%&'&($#($)*'$+,*'$)#$*%-#.*'/$0#1,2&.#34$5$6*(.#7.348
Baseia-se em 2 objetos:
! 9($*%-#.*$!"#$%&'"34$:*(+#(#$#2$(')*+,$)#$'&2;)&$<=#$
String a ser devolvida pelo HttpResponse
Template (geralmente HTML) com alguns marcadores
<=#>#1*'$)#?*2?#>$#($#2$@A,B#',*('#$3(*>1&21#(.#$
especiais de Django.
@0CD4E$,#>*$;(:2=5#()*$#+<=#.&'$#',#:;&2#'$)#$F-&(G*8
! 9($*%-#.*$-.+'"/'34$:*(+#(#$=($0*11*.+&)*.$:*($2*'$
?&2*>#'$<=#$)&($:*(.#7.*$&$=(&$,2&(+22&E$2*'$<=#$)#%#($
Um dicionário com os valores a serem
='&>'#$,&>&$>#()#>;H&>$=($*%-#.*$0#1,2&.#348
Context
renderizados no Template.

0#1,2&.#/ "Bienvenido, {{ user }}."
"Bienvenido, alatar."
6*(.#7./ {'user': 'alatar'}



!"#$%&'"(
Exemplo 1
! :(
)*+#"*&"#$%&'()#*(+,"#-"&./012&3"!"#$%&'",-,./0'"1'

from django.template import Template, Context

PLANTILLA = """<html><body>
Son las {{ hora }}.
</body></html>"""

def hora_actual(request):
t = Template(PLANTILLA)
c = Context({'hora': now})
html = t.render(c)



!"#$%&'"(
Exemplo 2
! )"*+,-&"#$%&'()#*(+,"#-"&./012&3".$",/0123"&-/0124%.("/0
:|
from django.template import Template, Context

fp = open('/home/django/templates/hora.html')
t = Template(fp.read())
fp.close()
html = t.render(c)



!"#$%&'"(
Exemplo 3
!:)!")*")&"#$%&'()#*(+,"#-"&./012&3"+"','"#$%&'"-.
TEMPLATE_DIRS = (
405,647$8 '/home/django/templates',
)

from django.template.loader import get_template
from django.template import Context

t = get_template('hora.html')
html = t.render(c)


!"#$%&'"(
Exemplo 3
! !")*")&"#$%&'()#*(+,"#-"&./012&3"+"','"#$%&'"-.
:D
TEMPLATE_DIRS = (
405,647$8 '/home/django/templates',
)

from django.template.loader import get_template
from django.template import Context

t = get_template('hora.html')
html = t.render(c)


!"#$%&'"(
Exemplo 4
:O
! "#$%&'()*+,*-.*/(0))"*+"),'-,)"($-*("./
from django.shortcuts import render_to_response

return render_to_response('hora.html', {'hora': now})



!"#$%&'"()*!+$
!"#$%&'"()*!+$
!"#$%&'"()*!+$
Lembrete!
!"#$%&'"()*!+$
!+,-".
)"* +,-".
TEMPLATE_DIRS = (

),-/".! ,-".
&, !"#$%!&'(
''! *
TEMPLATE_DIRS = (
+ +" +
'/home/django/templates',
&, !"#$%!&'( ) '/home/django/templates',

&, !"#$%!&'(
&, !"#$%!&'( )
TEMPLATE_DIRS =
TEMPLATE_DIRS = ((
'/home/django/templates',
'/home/django/templates', *!
)"*!)"+''!/
-, ) )
;-4"3$+<8+.3"*<-9=+,-"> +''!/ ''!/
+
-, -, ;-4"3$+<8+.3"*<-9=+,-">
TEMPLATE_LOADERS = (
;-4"3$+<8+.3"*<-9=+,-">
'django.template.loaders.filesystem.load_template_source',

-, ;-4"3$+<8+.3"*<-9=+,-">
'django.template.loaders.app_directories.load_template_source',
)
01+.2+3'"4+./templates."!.,*!2+5+.5"$436.5".2+5+.+''&
)
) 'django.template.loaders.filesystem.load_template_source',
0 'django.template.loaders.app_directories.load_template_source',
76$89"$".9$2-*93.*$+.2+3'"4+.26$."-.$6:,3".5".-+.+''.'63.2-+395+5&
) 0 1+.2+3'"4+./templates."!.,*!2+5+.5"$436.5".2+5+.+''&

0 1+.2+3'"4+./templates."!.,*!2+5+.5"$436.5".2+5+.+''&
0 76$89"$".9$2-*93.*$+.2+3'"4+.26$."-.$6:,3".5".-+.+''.'63.2-+395+5&
return render_to_response('website/index.html')

0 1+.2+3'"4+./templates."!.,*!2+5+.5"$436.5".2+5+.+''&
0 76$89"$".9$2-*93.*$+.2+3'"4+.26$."-.$6:,3".5".-+.+''.'63.2-+395+5&

0 76$89"$".9$2-*93.*$+.2+3'"4+.26$."-.$6:,3".5".-+.+''.'63.2-+395+5&


Templates: {{}}
!"#$%&'"()*++,,
Sintaxe simples de templates
<html>
<head>Ejemplo templates</head>
Desacoplado de Python <body>
Hola, {{ username }}.
</body>
HTML com anabolizantes </html>

Extensível
{'username': 'juan'}
Designers vão se apaixonar!

<html>
Templates não podem <body>
Hola, juan.
executar </body>
</html>
código Python!!!!



Templates: {{}}

Tags


!"#$%&'"()*'&+(*,-*-.
Tags
/0##"1' {% comment %} Bu! {% endcomment %}

203 {% for elemento in lista %}
<li>{{ elemento }}<li>
{% endfor %}

42 {% if username == "Juan" %}
Hola Juan, me gustas!
== != > < >= <=
in and or not
{% else %}
Hola {{ username }},
{% endif %}



!"#$%&'"()*+,%'"-(
Filters
<html>
.'%" <body>
Hola, {{ username|title }}.
</body>
</html>

{'username': 'juan'}

<html>
<body>
Hola, Juan.
</body>
</html>



Filters
!"#$%&'"()*+,%'"-(
{'value': 123456789}

&.. {{ value|add:”1” }} 123456790

/%"(,0"12-#&' {{ value|filesizeformat }} 117.7MB

{'date': datetime.datetime(2010, 9, 11, 17, 1, 59, 385323) }

.&'" {{ date|date:”d M Y” }} 11 Sep 2010

3#"(,45" {{ date|timesince }} 4 days, 6 hours

3#"643% {{ date|timeuntil }} 1 days, 6 hours



Modelos
Nós temos objetos e queremos persistí-los

Mapeamento entre Objetos e tabelas

Django tem ORM!



!"#$%"
Eu crio classes e objetos

from django.db import models

class Books(models.Model):
name = models.CharField(blank=True, max_length=100)
created = models.DateTimeField(blank=False)
available = models.BooleanField(default=True)

!"&'#$($'#$')*+",-./0
!"#$%&'()*"$*+,-.+-,/*"0$"'&1),(/.'2&"1$'23*)+43
!"#$%&'()*"3$453*))*"'$4"!"#$"%&&'()&*"+'(,*-.&/"01$2223
!"6'*)+"0$%&'.'2&"0$4"()0$4)"!4#"50%6*478"'(,*9/#(*(:)3"


!"#$%&'(&)$*+,
O ORM converte para SQL

BEGIN;
CREATE TABLE "website_books" (
"id" integer NOT NULL PRIMARY KEY,
"name" varchar(100) NOT NULL,
"created" datetime NOT NULL,
"available" bool NOT NULL
);
COMMIT;

BEGIN;
CREATE TABLE "website_books" (
"id" serial NOT NULL PRIMARY KEY,
"name" varchar(100) NOT NULL,
"created" timestamp with time zone NOT NULL,
"available" boolean NOT NULL
);
COMMIT; Residência de Reuso - 2011.1 - Recife/PE


Com 1 comando!




Conﬁgure o seu banco
!"#$%&'(')*+,#%*-./

DATABASE_ENGINE = 'sqlite3'
DATABASE_NAME = 'db.sqlite'
DATABASE_USER = ''
DATABASE_PASSWORD = ''
DATABASE_HOST = ''
DATABASE_PORT = ''

settings.py



e se alterar os modelos ?
Não atualiza os esquemas existentes! :(
GoHorse: Dropa na mão e rexecuta syncdb!

Ou aplicações externas:

south
desed
django-evolution
yasdel



Exemplo !"#$%&
Creating table auth_permission
Creating table auth_group
Creating table auth_user
Creating table auth_message
Creating table django_content_type
Creating table django_session
Creating table django_site
Creating table website_tweet

You just installed Django's auth system, which means you don't have any
superusers defined.
Would you like to create one now? (yes/no): yes
Username (Leave blank to use 'neo'): admin
E-mail address: user@example.com
Password:
Password (again):
Superuser created successfully.
Installing index for auth.Permission model
Installing index for auth.Message model
Installing index for website.Tweet model



Exercício 03

Criar o backend da sua app seminarios

Vamos usar o sqlite3



Exemplo

Hora de fazer montar consultas!


ORM- Consultas
!"#$%&'()*+,#,(-#*(./0
$ python manage.py shell

select * from publisher;

ts = Publisher.objects.all()

Model

Manager

QuerySet



!"#$%&'())*+%,&-#))./
ORM- Consultas
>>> Publisher.objects.all()
[<Publisher: Publisher object>]

class Publisher(models.Model):
...

def __unicode__(self):
return self.name

[<Publisher: Apress>]



ORM- Inserção
!"#$%&
o = Model(...) o.save()

!" >>> p = Publisher(
... name='Apress',
... address='2855 Telegraph Avenue',
... city='Berkeley',
... state_province='CA',
... country='U.S.A.',
... website='http://www.apress.com/')
>>> p.save()



!"#$%&
!"#$%&
ORM- Atualização o.save()

o.save()
>>> ...
>>> p.id
! >>>
52
>>>
...
p.id
>>> p.name = 'Apress Publishing'
! 52
>>> p.save()
>>> p.name = 'Apress Publishing'
>>> p.save()

queryset.update(...)

" >>> Publisher.objects.all().update(country='USA')
2



!"#"$"
o.delete()
ORM- Deleção
>>> ... o.delete()
>>> p.id
! 52
>>> ...
>>> p.delete()
>>> p.id
! 52
>>> p.delete()
queryset.delete()

>>> ps = queryset.delete()
Publisher.objects.all()
" >>> ps.delete()

>>> ps = Publisher.objects.all()
" >>> ps.delete()



!"#"$%&'(&)&*(+,-./'0
!"#"$%&'(&)&*(+,-./'0
Select 1 resultado
.get(...)
.get(...)
.get(...)

>>> Publisher.objects.get(name="Apress")
<Publisher: Apress>
<Publisher: Apress>
<Publisher: Apress>

>>> Publisher.objects.get(name="Anaya")
>>> >>> Publisher.objects.get(name="Anaya")
Publisher.objects.get(name="Anaya")
...
... ...
DoesNotExist: Publisher matching query does not exist.
DoesNotExist: Publisher matching query does exist.
DoesNotExist: Publisher matching query does not not exist.

>>> Publisher.objects.get(country="U.S.A.")
>>> >>> Publisher.objects.get(country="U.S.A.")
Publisher.objects.get(country="U.S.A.")
...
... ...
MultipleObjectsReturned: get() returned more than one Publisher --
MultipleObjectsReturned: get() returned more than Publisher --
MultipleObjectsReturned: get() returned more than one one Publisher --
it returned 2! Lookup parameters were {'country': 'U.S.A.'}



!"#"$%&'(&)&*(+,-./'0+
Select n resultados
!"#"$%&'(&)&*(+,-./'0+
!"#"$%&'(&)&*(+,-./'0+ .all()

.all()
.all()
[<Publisher: Apress>, <Publisher: O'Reilly>]
.filter(...)

.filter(...)
>>> Publisher.objects.filter(
.filter(...)
country="U.S.A.", state_province="CA")

RETORNAM QUERYSETS e não LISTAS!



!"#$%&'()#"*$%'+'",-)./"$%
Manipulação de consultas
!"#$%&'()#"*$%'+'",-)./"$%
Modelo.objects.filter(campo1="valor1", campo2="valor2")

!"#$%&'()*+'"#$%,*-*.$/.-/0&'$),01"$)(#$2,*$/3,&4-&-$567
Modelo.objects.filter(campo1="valor1", campo2="valor2")

!"#$%&'()*+'"#$%,*-*.$/.-/0&'$),01"$)(#$2,*$/3,&4-&-$567
campo__exact='' campo__gt=0 campo__startswith=''
campo__iexact='' campo__gte=0 campo__istartswith=''
campo__contains='' campo__lt=0 campo__endswith=''
campo__icontains='' campo__gt=0
campo__exact='' campo__lte=0 campo__iendswith=''
campo__startswith=''
campo__isnull=T|F
campo__iexact='' campo__gte=0 ,] campo__istartswith=''
campo__in=[ campo__range=( ,)
campo__day=31
campo__contains='' campo__month=12 campo__endswith=''
campo__lt=0 campo__year=2010

campo__icontains='' campo__lte=0 campo__iendswith=''
campo__isnull=T|F campo__in=[ ,] campo__range=( ,)
campo__day=31 campo__month=12 campo__year=2010


Order!"#$"%&'
By
!"#$"%&'
.order_by(...)
.order_by(...)

>>> Publisher.objects.order_by("name")
>>> Publisher.objects.order_by("name")

>>> Publisher.objects.order_by("-name")
>>> Publisher.objects.order_by("-name")
[<Publisher: O'Reilly>, <Publisher: Apress>]

!"#$%#&'()*+%,'-
!"#$%#&'()*+%,'-
>>> Publisher.objects.order_by("-name", "country")
>>> Publisher.objects.order_by("-name", "country")


!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
Relacionamentos One-to-One
OneToOneField
OneToOneField
OneToOneField
class OneToOneField
classCoche(models.Model):
Coche(models.Model):
44 class Coche(models.Model):
motor = =OneToOneField(Motor)
motor OneToOneField(Motor)
1 4 class Coche(models.Model):
motor = OneToOneField(Motor)
4 motor = OneToOneField(Motor)
class Motor(models.Model):
class Motor(models.Model):
44 class Motor(models.Model):
...
...
4 class Motor(models.Model):
...
14 ...
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
3+)-.)(&)&/%(%1+%(
3+)-.)(&)&/%(%1+%( 3+)-.)(&)&-*$./0
3+)-.)(&)&-*$./0
3+)-.)(&)&/%(%1+%(
>>> c.motor
>>> c.motor
3+)-.)(&)&-*$./0
>>> m.coche
>>> m.coche
3+)-.)(&)&/%(%1+%(
<Motor: Motor object>
>>> c.motor
3+)-.)(&)&-*$./0
<Coche: Coche object>
<Coche: Coche object>
>>> m.coche
>>> c.motor <Coche: Coche object>
>>> m.coche
<Motor: Motor object> <Coche: Coche object>


!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
Relacionamentos One-to-Many
!"#$%"&'()*"+%,
ForeignKeyField
ForeignKeyField
ForeignKeyField
44
ForeignKeyField
class Blog(models.Model):
...
...
1 4
...
4 ...
class Post(models.Model):
// blog ==ForeignKeyField(Blog)
blog ForeignKeyField(Blog)
/
n / class Post(models.Model):
blog = ForeignKeyField(Blog)
blog = ForeignKeyField(Blog)
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
3+)-.)(&)&/%(%1+%(
3+)-.)(&)&/%(%1+%( 3+)-.)(&)&-*$./0
3+)-.)(&)&-*$./0
3+)-.)(&)&/%(%1+%(
>>> p.blog
>>> p.blog >>> 3+)-.)(&)&-*$./0
>>>b.post_set.all()
b.post_set.all()
3+)-.)(&)&/%(%1+%(
<Blog: Blog object>
<Blog: Blog object> 3+)-.)(&)&-*$./0
[<Post: Post object>, ...]
>>> p.blog >>> b.post_set.all()
>>> p.blog
<Blog: Blog object> >>> b.post_set.all()
<Blog: Blog object> [<Post: Post object>, ...]


!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
Relacionamentos Many-to-Many
ManyToManyField
ManyToManyField
// ManyToManyField
ManyToManyField
tags == ManyToManyField(Tag)
tags ManyToManyField(Tag)

m/ class Post(models.Model):
/
$
$
class Tag(models.Model):
tags = ManyToManyField(Tag)
tags = ManyToManyField(Tag)
...
...

n $
$
...
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
...

3+)-.)(&)&/%(%1+%(
3+)-.)(&)&/%(%1+%( 3+)-.)(&)&-*$./0
3+)-.)(&)&-*$./0
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
!"#$%&'()$%(&*)&+,*)-.#/&0,(0,&*)(&./(1)/-.)(2
>>> p.tags.add(t1, t2)
>>> p.tags.add(t1, t2) >>> t.post_set.add(p1, p2)
>>> t.post_set.add(p1, p2)
>>> 3+)-.)(&)&/%(%1+%(
>>> p.tags.all()
p.tags.all() 3+)-.)(&)&-*$./0
>>> t.post_set.all()
3+)-.)(&)&/%(%1+%(...]
[<Tag: Tag object>, ...]
[<Tag: Tag object>,
3+)-.)(&)&-*$./0 ...]
[<Post: Post object>,
>>> p.tags.add(t1, t2)
>>> p.tags.add(t1, t2) >>> t.post_set.add(p1, p2)
>>> t.post_set.add(p1, p2)
>>> p.tags.all()
>>> p.tags.all() >>> t.post_set.all()
[<Tag: Tag object>, ...]
[<Tag: Tag object>, ...] [<Post: Post object>, ...]
[<Post: Post object>, Recife/PE
Residência de Reuso - 2011.1 - ...]

!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
!"#$%"&'()*"+%,
Ponteiros inversos
!"#$%&'(#)**'(#+%&),%(#-"./0)-$-#)*#+-"$).%#/"0).(%
!"#$%&'(#)**'(#+%&),%(#-"./0)-$-#)*#+-"$).%#/"0).(%
!"#$%&'(#)**'(#+%&),%(#-"./0)-$-#)*#+-"$).%#/"0).(%
1classclass Blog(models.Model):
+ classBlog(models.Model):
Blog(models.Model):
++ ...
...
...
...

( classPost(models.Model):
(( n
blog = ForeignKeyField(Blog, related_name='posts')
blog = ForeignKeyField(Blog, related_name='posts')
blog = = ForeignKeyField(Blog, related_name='posts')
blog ForeignKeyField(Blog, related_name='posts')

!"#$%#&'#'()&)*")& !"#$%#&'#'1*$.2/
!"#$%#&'#'()&)*")&
!"#$%#&'#'()&)*")& !"#$%#&'#'1*$.2/
!"#$%#&'#'1*$.2/
>>> p.blog
>>> p.blog >>> b.posts.all()
>>> b.posts.all()
>>> <Blog: Blog object>
p.blog
>>> p.blog >>> [<Post: Post object>, ...]
b.posts.all()
>>> b.posts.all()
<Blog: Blog object>

1-'"&%#2'3'#3'-"#$+4/.",'".%-"'3'0/&"#/,4#().5#/)#42$%/-4/
1-'"&%#2'3'#3'-"#$+4/.",'".%-"'3'0/&"#/,4#().5#/)#42$%/-4/
1-'"&%#2'3'#3'-"#$+4/.",'".%-"'3'0/&"#/,4#().5#/)#42$%/-4/


Laziness
!"#$%&''
!"#$%&''
#$%&'($)*+#$%'()*%$,%,-,&)+#./(%&)#(0'%.,#*1,(+,%$,%
Otimização!! Consulta só realizada quando necessário!
,&,$2+,%'3+,(,.%*'$%'3-,+'$4%5(%*#$%$26)2,(+,$%$2+)#&2'(,$7
#$%&'($)*+#$%'()*%$,%,-,&)+#./(%&)#(0'%.,#*1,(+,%$,%
! 8+,.#&2'(,$
,&,$2+,%'3+,(,.%*'$%'3-,+'$4%5(%*#$%$26)2,(+,$%$2+)#&2'(,$7
for p in Publisher.objects.all():

! 8+,.#&2'(,$
! 9*2&2(6 for p in Publisher.objects.all():
Publisher.objects.filter(country='USA')[0]

! 9*2&2(6
! 9,.2#*2:#&2;( Publisher.objects.filter(country='USA')[0]
<=#&>?@

! 9,.2#*2:#&2;(
• repr() <=#&>?@
[<Publisher: Publisher object>]

• len() !!!
repr() [<Publisher: Publisher object>]
len(Publisher.objects.all())

• list() !!!
len() len(Publisher.objects.all())
list(Publisher.objects.all())

• bool()
list()
list(Publisher.objects.all())
if Publisher.objects.filter(country='USA'):

Exercício 04

!"#$%&!'()*(+&"(*',(-(+&#./)*(&0&$(1(*(


Interface Administrativa



djang.contrib.admin
Instalação 1/3



djang.contrib.admin
!"#$%&'#()*$+',$-.#/#0*1$ Instalação 2/3

!"#$%!&'(

INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.admin', 1
...
)



!"#$%&'(%)*+,&%,-.
djang.contrib.admin
!"#$%&'(%)*+,&%,-.
Instalação 3/3


Creating table django_admin_log
Creating table django_admin_log
Installing index for admin.LogEntry model
Installing index for admin.LogEntry model

Acesse http://localhost:8000/admin
!"#$%&'$()*&+*,*&-(*,
!"#$%&'$()*&+*,*&-(*, Residência de Reuso - 2011.1 - Recife/PE


!"#$%&'(
Opa! Falta registrar os modelos
! "#$#%!''%$&'&%$&%(&)&*%&+%,-./0
! 1&2)&%3-4%5/$&+/,%,&*6)%78,8'+&,%$&,$&%&+%#$58)%.%
Criar o módulo admin.py
9&*58(&%9&*,/)#+8:#*%,-%#,9&;(/0 ser conﬁgurável!
Cada app deve ter o seu, pode

from django.contrib import admin
from website.models import Tweet

class TweetAdmin(admin.ModelAdmin):
list_display = ('id','user','message','timestamp')

admin.site.register(Tweet, TweetAdmin)



Exercício 04

!"#$%&'#(") Residência de Reuso - 2011.1 - Recife/PE


!"#$%$&'()*"+,-#.#$
!"#$%$&'()*"+,-#.#$
Forms
3 componentes
Widget
Widget !"#$"%&%'&()'$+#"(&)*+,-.&%'&(-(/012
!"#$"%&%'&()'$+#"(&)*+,-.&%'&(-(/012
Componente Visual
Widget !"#$"%&%'&()'$+#"(&)*+,-.&%'&(-(/012
Widget TextInput <input type='text'...>
TextInput <input type='text'...>
TextInput <input type='text'...>
CheckboxInput <input type='checkbox'...>

Field
Field /01',#(3&(*%(4-#$"5(-6"4+-3"(-(*%(7+38&'
/01',#(3&(*%(4-#$"5(-6"4+-3"(-(*%(7+38&'
Field /01',#(3&(*%(4-#$"5(-6"4+-3"(-(*%(7+38&'
Campo Lógico
EmailField
Field EmailField
EmailField widget, initial, error, ...
IPAddressField widget, initial, error, ...
IPAddressField widget, initial, error, ...
IPAddressField

Form
Form !*(2+(3*(3&(9+&.36(3&(*%(:";#*.-;+"
Formulário em si
Form
Form !*(2+(3*(3&(9+&.36(3&(*%(:";#*.-;+"
!*(2+(3*(3&(9+&.36(3&(*%(:";#*.-;+"
ContactForm [nombre, email, telefono, mensaje, ...]


Criação de Formulário
Passo 1: Deﬁnição de um formulário forms.py

http://docs.djangoproject.com/en/dev/ref/forms/ﬁelds/



Passo 2: Deﬁnição do template do Formulário

contato.html



Passo 3: Deﬁnição da view do Formulário



!"#$%"&$'()*+,*$"
!"#$%"&'()"*)+%+)',+-.#+/.01'$23)+'+&"/.+#+'+'/+#+'4.$-#'
Forms tem validação própria! Cool :D
#$-'5")%6-+)."'$&/).7.$1#"'61'%83"#"'clean_<fieldname>9

from django import forms

class ContactForm(forms.Form):
subject = forms.CharField(max_length=100)
email = forms.EmailField(required=False)
message = forms.CharField(widget=forms.Textarea)

def clean_message(self):
message = self.cleaned_data['message']
num_words = len(message.split())
if num_words < 4:
raise forms.ValidationError("Not enough words!")
return message



Forms a partir de Models
!"#$%&'&('#)#&*+&,"*+-% Aqui é DRY meu caro!!

from django.db import models

class Author(models.Model):
!"#$%&'() name = models.CharField(max_length=100)
birth_date = models.DateField(blank=True, null=True)
country = models.ModelChoiceField(Country)
...

from django import forms
from books.models import Author

."#$%/(0 class AuthorForm(forms.ModelForm):
class Meta:
model = Author
exclude = ('country',)



Exercício 04

Alguns truques agora...


Django Avançado

1. Middleware
2. Caching
3. Deploying
4. Apps Recomendadas



!"##$%&'(%
Middleware
Permite incrementar a funcionalidade injetando ﬂuxo de
!"#$%&'()*&$&#+'),)'$-./+)"/01)202$'&.31)40,1&$
execução em Django
5.&$#&$)/#&'*0$&/$&1$6.7"$2&$&7&+.+)8/$2&$970/:"



Middleware
!"##$%&'(%
class MyMiddleware(object):

def process_request(self, request):
"""Se ejecuta antes de que Django decida a quâˆ!Â© View llamar.
-> HttpRequest(): Se corta el flujo de middleware.
-> None: El flujo sigue con el siguiente middleware."""
# ...

def process_view(self, request, view_func, view_args, view_kwargs):
"""Se ejecuta antes de que se llame a la View.
-> HttpRequest(): Se corta el flujo de middleware.
-> None: El flujo sigue con el siguiente middleware."""
# ...

def process_response(self, request, response):
"""Se ejecuta despuâˆ!Â©s de que la View devuelva una response.
-> HttpResponse()"""
# ...

def process_exception(self, request, exception):
"""Se ejecuta cuando una View lanza una excepciâˆ!â‰¥n.
-> HttpResponse().
-> None: La excepciâˆ!â‰¥n se propaga hasta el cliente."""
# ...



!"##$%&'(%
Middleware
!"#"$%&'()"'*#+,)*-'#)"&.-%'$*//,"01-"'"#'",',)21-'
()"'#%&'+%#3"#214')%*"%*#+,%*,-.%*)',%$,+(#%*,#%,
%/%-.-"0*,%*,$',1%2.%3),4,%*,$',1%35+*3%5
Registrar o middlewares no settings.py

MIDDLEWARE_CLASSES = (
'django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
)



Caching
!"!#$%&
Sempre importante estar aliviando o banco de consultas...
'$()*
!"!#$%&
from django.views.decorators.cache import cache_page

@cache_page(60 * 15)
def my_view(request):
'()*'+,+' ...

>>> from django.core.cache import cache
>>> cache.set('my_key', 'hello, world!', 30)
>>> cache.get('my_key')
'hello, world!'


! "#$%&#'()*)+%*,()-*./-0%,(12#($%(#34%5#(/-%('%(2-%$*('%,0*.06*,7

Deploying
Por o sistema em produção

VirtualEnv + PIP + Fabric



!"#$%&'()*
! "#$%&%#$%#'()*'+,&-%.)*$%*-)/*-(01%12)/*$%-*/(.%,)3
Virtualenv
! 4)$)*&1+5%'.+*6%#%*/7*87%9+*$%*-(01%12)/*%#*-)*:%1/(;#*<7%*#%'%/(.)
"#$%&%#$%#'()*'+,&-%.)*$%*-)/*-(01%12)/*$%-*/(.%,)3
! =(#*,(%$+*)*)'.7)-(>)1
! 4)$)*&1+5%'.+*6%#%*/7*87%9+*$%*-(01%12)/*%#*-)*:%1/(;#*<7%*#%'%/(.)
! =(#*,(%$+*)*,(91)1
=(#*,(%$+*)*)'.7)-(>)1
Projeto independente do sistema
! %.'333
=(#*,(%$+*)*,(91)1
Ou seja cada projeto com suas dependências
! %.'333
+#(&# especíﬁcas
+#(&# $ virtualenv --no-site-packages mi_entorno
$ virtualenv --no-site-packages mi_entorno
&+,*&#
$ source mi_entorno/bin/activate

Adeus dor de cabeça de migrar, atualizar, etc.



Pip
!"!
!"!
! "#$%&'()#(*+,-#%#$()#.($/0.&(12(34
Gerenciador de Pacotes
! ! 5#'6/%#(#$*#7/87+'(-9(87:#'&()#(;<=>?;<@<ABC(7&9(-9(./$%+)&()#(
"#$%&'()#(*+,-#%#$()#.($/0.&(12(34
! 5#'6/%#(#$*#7/87+'(-9(87:#'&()#(;<=>?;<@<ABC(7&9(-9(./$%+)&()#(
*+,-#%#$(+(/9$%+.+'D uma lista de requisitos (requirements)
Você pode criar
*+,-#%#$(+(/9$%+.+'D
para instalação automática! :D
4E+90&FF2D1D2
4E+90&FF2D1D2
*$G7&*01
*$G7&*01
H##)*+'$#'FFID2
H##)*+'$#'FFID2
$%'/*&0'+6FF2DJ
$%'/*&0'+6FF2DJ
"K:+'%L'+**#'FFMDN
"K:+'%L'+**#'FFMDN

pip install -E mi_entorno -r REQUIREMENTS
pip install -E mi_entorno -r REQUIREMENTS



!"#$%&
Fabric !"#$%&
““ Repetition leads to boredom, boredom to horrifying mistakes,
“Repetition leads to boredom, boredom to horrifying mistakes,
horrifying mistakes to God-I-wish-I-was-still-bored
Repetition leads to boredom, boredom to horrifying mistakes,
horrifying mistakes to God-I-wish-I-was-still-bored”
horrifying mistakes to God-I-wish-I-was-still-bored
'"#()*+,-
'"#()*+,-
env.user = "example"
env.hosts = ["example.com"]
def deploy():
env.user = "example"
run('svn up /home/example/')
env.hosts = ["example.com"]
sudo('/etc/init.d/lighttpd restart')
def deploy():
run('svn up /home/example/')
sudo('/etc/init.d/lighttpd restart')

./0
fabric deploy



%6*896(,%;6*8968.1<+,=>%
%?/,0'2(,/%
%?/,0'2(,/%*.3#:,(,%
django-registration
%?/,0'2(,/%*:.2,4%
%?:.0'1%
%?:.0.)(%
%?#622@./4%*!610,%
Sistema completo de cadastro de usuários
%?#622@./4%*!610,%4.1,%
%?#622@./4%/,2,(% DRY!!
%?#622@./4%/,2,(%*.1A/3%;(.+,1>
%?#622@./4%/,2,(%*.3#:,(,%
Instalação Copy and Paste
%?#622@./4%/,2,(%4.1,%
%?/,6*896(,%

!"#$%%&'(&)*+,(-./0%)&,/1.2(/)3%45610.7/,0'2(/68.1%



django-socialregistration
; <-2=&)80,'>2?192,'770
; @)(92:,0,'>2?,-2$
O django-registration só que anabolizado!
; (A'"98B?C0,9*--3B?-0)(!B?-#92'4
; D2(9&80,'>2?#98C9,(0?,-2?,-2(8'*+0)(!
Autenticação com Twitter, Facebook, oAuth, openID

Integração perfeita com django.contrib.auth

!"#$%%&'(!)*+,-.%/01!'2&#).#3'2%4502&-61-,'0789&'1(80:-2



django-piston
: ;</59,7./+;#5/5;*/,5/;=>?2;@ABCD)E
: ;F)G;DH*'E;'32(5E5*'I3 !"#$%&'()*+&$
Framework Django para construção de serviços RESTful
: ;B,/'5E'J5*'I3;5$
Fácil de instalar
: ;</59,7./+;#5/5;*/,5/;=>?2;@ABCD)E
: KBLMN;O=FPN;>G(!.3;>G*+E,N;QFP;---
: ;F)G;DH*'E;'32(5E5*'I3
Suporte para YAML, JSON, XML, etc.
: ;B,/'5E'J5*'I3;5$
: L=)(!
OAuth
: KBLMN;O=FPN;>G(!.3;>G*+E,N;QFP;---
: @,*.9,3454.;RRRRR : L=)(!
: @,*.9,3454.;RRRRR

!"#$%%&'(&)*+,(-./0%1,2#,/3%41530.6#'2(.3%7'+'%8.9,
!"#$%%&'(&)*+,(-./0%1,2#,/3%41530.6#'2(.3%7'+'%8.9,



Apenas uma ponta do iceberg


Lembre-se da comunidade!
http://python.org.br
http://djangobrasil.org
http://pug-pe.python.org.br
#django-br
#python-br



Trabalho da Semana
Trabalho para 5 pessoas
Criar um sistema em Django com o assunto visto até aqui
O sistema deve ter no mínimo 10 entidades
O sistema deve ter controle de acesso
(ver django-registration)
Modelagem vocês decidem
Apresentar pontos positivos e negativos durante o uso da
tecnologia



Referências
Desenvolvimento web com Python e Django
http://www.slideshare.net/igorsobreira/desenvolvimento-web-com-python-e-django

Django: Disfruta Programando
http://www.slideshare.net/etox/django-eghost-2010

Tutoriais DjangoBrasil
http://docs.djangobrasil.org/intro/tutorial01.html



Bibliograﬁa
The Definitive Guide to Django: Web Development Done Right. Adrian
Holovaty, Jacob K. Ed. Appress ISBN-13: 978-1430219361

Pro Django (1st ed.) Marty Alchin. 2008. . Apress, Berkely, CA, USA. ISBN -
1430210478

Python e Django - Desenvolvimento Ágil de Aplicações Web - Osvaldo
Santana Neto e Thiago Galesi; Editora Novatec ISBN. 9788575222478.



Exercício 01
Vamos construir um mini-sistema de submissão
de palestras do nosso seminário

1. Criar um projeto seminario
2. Criar uma app trabalhos
3. Criar uma view index redirecionando para
uma página html de boas vindas usando
templates.



Exercício 05

Vamos criar a nossa interface administrativa para o nossos
modelos recém-criados



Exercício 04

Vamos criar os modelos para Trabalho e Palestrante

Trabalho
usuario: User
titulo: String Palestrante
descricao: String 1. * * name
slides: File
status: Integer



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