Django1.8教程重点

1 create project

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django-admin startproject *project-name*

基本设置 settings.py

Database:
default->sqlite3

DATABASES = {    'default': {        'ENGINE': 'django.db.backends.sqlite3',         #’django.db.backends.postgresql_psycopg2’,’django.db.backends.mysql’, or ’django.db.backends.oracle’        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),        #filename and path of .db    }}

other database should set ‘USER’,’PASSWORD’,’HOST’

TimeZone:
TIME_ZONE = 'UTC'

INSTALLED_APPS:
需要运行的APP
- django.contrib.admin – The admin site. You’ll use it in part 2 of this tutorial.
- 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.

note: 要使用这些app必须要创建数据库表
python manage.py migrate
指令检查 这些应用的settings，并建立表。

开发用服务器

python manage.py runserver
使用其他端口
python manage.py runserver 0.0.0.0:8080

2 Create Models(数据模型)

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project vs app： 一个项目可以有很多app

创建app

python manage.py startapp polls
在这个app中我们创建俩种数据。放在polls/models.py中。

class Question(models.Model):     question_text = models.CharField(max_length=200)    pub_date = models.DateTimeField(‘date published’)class Choice(models.Model):     question = models.ForeignKey(Question)     choice_text = models.CharField(max_length=200)     votes = models.IntegerField(default=0)

更新数据models

在mysite/settings.py的 INSTALLED_APPS中加入polls

INSTALLED_APPS= ( ‘django.contrib.admin’, ‘django.contrib.auth’, ‘django.contrib.contenttypes’,‘django.contrib.sessions’, ‘django.contrib.messages’, ‘django.contrib.staticfiles’, ‘polls’, )

创建migration（这是一个中间记录迁移记录，并不会更新数据库，只是记录当前的数据库更新，而且还是泛型的）
python manage.py makemigrations polls
显示migration的具体的sql语句（针对某一个sql）
python manage.py sqlmigrate polls 0001
真正的更新数据库：
python manage.py migrate

3 Django Shell

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进入项目的shell
python manage.py shell

创建数据项、数据项操作

>>> from polls.models import Question, Choice # Import the model classes we just wrote.# No questions are in the system yet.>>> Question.objects.all()[]# Create a new Question.# Support for time zones is enabled in the default settings file, so# Django expects a datetime with tzinfo for pub_date. Use timezone.now()# instead of datetime.datetime.now() and it will do the right thing.>>> from django.utils import timezone>>> q = Question(question_text="What's new?", pub_date=timezone.now())# Save the object into the database. You have to call save() explicitly.>>> q.save()># Now it has an ID. Note that this might say "1L" instead of "1", depending# on which database you're using. That's no biggie; it just means your# database backend prefers to return integers as Python long integer# objects.>>> q.id1# Access model field values via Python attributes.>>> q.question_text"What's new?">>> q.pub_datedatetime.datetime(2012, 2, 26, 13, 0, 0, 775217, tzinfo=<UTC>)# Change values by changing the attributes, then calling save().>>> q.question_text = "What's up?">>> q.save()# objects.all() displays all the questions in the database.>>> Question.objects.all()[<Question: Question object>]

4 创建admin用户

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1.python manage.py createsuperuser
2.启动开发服务器python manage.py runserver
3.进入/admin/域名，会显示数据库的表
4.将Question变得可编辑。在polls/admin.py中注册Question

from .models import Questionadmin.site.register(Question) 

5.进入修改数据项

自定义admin表

元素显示

1.重排Question中子元素顺序：fields

from .models import Questionclass QuestionAdmin(admin.ModelAdmin):     fields = [’pub_date’, ‘question_text’]admin.site.register(Question, QuestionAdmin) 

2.将子元素划分不同组：fieldsets

from .models import Questionclass QuestionAdmin(admin.ModelAdmin):     fieldsets = [ (None, {‘fields’: [’question_text’]}), (‘Dateinformation’,{‘fields’: [’pub_date’]}), ]admin.site.register(Question, QuestionAdmin)

3.为子元素指定HTML的class, 使用fields中设定’classes’属性

from .models import Questionclass QuestionAdmin(admin.ModelAdmin):     fieldsets = [ (None, {‘fields’: [’question_text’]}), (‘Dateinformation’,{‘fields’: [’pub_date’], ‘classes’: [’collapse’]}),]admin.site.register(Question, QuestionAdmin)

4.指定多外键inlines,stackedInline

from .models import Choice, Questionclass ChoiceInline(admin.StackedInline):     model = Choice     extra = 3class QuestionAdmin(admin.ModelAdmin):     fieldsets = [ (None, {‘fields’: [’question_text’]}), (‘Dateinformation’,{‘fields’: [’pub_date’], ‘classes’: [’collapse’]}),]     inlines = [ChoiceInline]admin.site.register(Question, QuestionAdmin) 

5.TarbularInline压缩式多外键，替换stackedInline

列表显示

1.列表显示的样式。admin.ModelAdmin的属性list_display，列表显示元素的属性，而不是只显示名字
list_display = (‘question_text’,‘pub_date’,‘was_published_recently’)
2.列表显示的功能。list_filter,search_fields
增加筛选和搜索功能

list_filter = ['pub_date']search_fields = ['question_text']

3.其他功能：
Change list pagination, search boxes, filters, date-hierarchies, and column-header-ordering all work together like you think they should.

自定义admin样式

1.polls下新建Templates文件夹。用以存放模板。
2.mysite/settings.py增加一个DIRS在TEMPLATES设置中。

TEMPLATES = [     {    ‘BACKEND’:‘django.template.backends.django.DjangoTemplates’,    ‘DIRS’: [os.path.join(BASE_DIR, ‘templates’)],     ‘APP_DIRS’: True,     ‘OPTIONS’: {         ‘context_processors’: [         ‘django.template.context_processors.debug’,        django.template.context_processors.request’,        ‘django.contrib.auth.context_processors.auth’,        ‘django.contrib.messages.context_processors.messages’,         ],     },     }, ]

3.在Templates文件夹下新建admin文件夹，将django的admin/base_site.html拷贝到此处。
4.自定义更改

5 VIEWS

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url和视图函数

django将URL与VIEWS对应。使用一个URLconfs转换。

1.polls/views.py写界面函数

from django.http import HttpResponsedef index(request):     return HttpResponse(“Hello, world. You’re at the polls index.”)

2.polls/urls.py 定向app的urls

from . import viewsfrom django.conf.urls import include, urlurlpatterns = [ url(r’^$’, views.index, name=’index’), ]

3.mysite/urls.py 包含到总urls

urlpatterns = [ url(r’^polls/’, include(‘polls.urls’)), url(r’^admin/’, include(admin.site.urls)), ]

4.url()函数参数
- regex字符：匹配字符
- view函数名
- kwargs：可以传递表，给视图函数
- name：模糊名，全局使用。可以在模板中使用

带参数的url

from django.conf.urls import urlfrom . import viewsurlpatterns = [# ex: /polls/ url(r’^$’, views.index, name=’index’), # ex: /polls/5/ url(r’^(?P<question_id>[0-9]+)/$’,views.detail, name=’detail’), #ex: /polls/5/results/ url(r’^(?P<question_id>[0-9]+)/results/$’,views.results,name=’results’), # ex: /polls/5/vote/ url(r’^(?P<question_id>[0-9]+)/vote/$’, views.vote, name=’vote’), ]def results(request, question_id)：    passdef detail(request, question_id)：    pass

“/polls/34/” 的Django调用方式
detail(request=, question_id=’34’)

高级的VIEW编写

1.读取数据库输出

from django.http import HttpResponsefrom .models import Questiondef index(request):     latest_question_list =Question.objects.order_by(‘-pub_date’)[:5]     output = ‘,‘.join([p.question_text for p in latest_question_list])    return HttpResponse(output)

2.使用模板 Templates
- 创建目录 polls/templates/polls/index.html
- 用template_loader以 polls/index.html访问
- 编写django定义的模板

模板有点类似于php了

{% if latest_question_list %}<ul> {% for question in latest_question_list %} <li><a href=”/polls/{{ question.id }}/”>{{ question.question_text}}</a></li> {% endfor %} </ul>{% else %} <p>No polls are available.</p> {% endif %}

• 重写view

from django.http import HttpResponsefrom django.template import RequestContext, loaderfrom .models import Questiondef index(request):    latest_question_list = Question.objects.order_by(‘-pub_date’)[:5] tem    plate = loader.get_template(‘polls/index.html’)     context = RequestContext(request, { ‘latest_question_list’: latest_question_list, })     return HttpResponse(template.render(context))

3.更简单的方式render()

from django.shortcuts import renderfrom .models import Questiondef index(request):     latest_question_list = Question.objects.order_by(‘-pub_date’)[:5]     context ={‘latest_question_list’: latest_question_list}      return render(request, ‘polls/index.html’, context)

4.返回404

from django.http import Http404 from django.shortcuts import renderfrom .models import Question # ... def detail(request, question_id):     try:         question = Question.objects.get(pk=question_id)    except Question.DoesNotExist:         raise Http404(“Question does not exist”)     return render(request,‘polls/detail.html’, {‘question’: question})

5.get_object_or_404(),get_list_or_404() 404的捷径

 from django.shortcuts import get_object_or_404,render from .models import Question def detail(request, question_id):      question = get_object_or_404(Question, pk=question_id)      return render(request, ‘polls/detail.html’, {‘question’: question})

模板系统

点查找

如下面的代码

<h1>{{ question.question_text }}</h1><ul> {% for choice in question.choice_set.all %}<li>{{ choice.choice_text }}</li>  {% endfor %} </ul>

• 属性查找question.question_text
  
  1. 首先字典查找
  2. 属性查找
  3. list-index查找
• 方法调用 question.choice_set.all实际上执行question.choice_set.all()。

模板类型

1. {{}}变量模板
2. {%url 'detail' question.question_id %}超链接模板，调用全局视图函数。
3. {% if var %} {% else %} {% endif %}
4. {% for var in list %} {% endfor %}

URL的名称域

在include函数中之中设置名称域

from django.conf.urls import include, urlfrom django.contrib import adminurlpatterns = [ url(r’^polls/’, include(‘polls.urls’,namespace=”polls”)), url(r’^admin/’,include(admin.site.urls)), ]

在模板中调用之中用’:’调用

<li><a href=”{% url ‘polls:detail’ question.id %}”>{{question.question_text}}</a></li>

表单

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前端form

<h1>{{ question.question_text }}</h1>{% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}<form action=”{% url ‘polls:vote’ question.id %}” method=”post”> {% csrf_token %} {% for choice in question.choice_set.all %} <input type=”radio” name=”choice” id=”choice{{ forloop.counter }}” value=”{{ choice.id }}”/> <label for=”choice{{ forloop.counter }}”>{{choice.choice_text }}</label><br /> {% endfor %} <input type=”submit” value=”Vote” /></form>

后台python

from django.shortcuts import get_object_or_404, render from django.http import HttpResponseRedirect, HttpResponse from django.core.urlresolvers import reversefrom .models import Choice, Question # ... def vote(request, question_id):     p = get_object_or_404(Question, pk=question_id)     try: selected_choice = p.choice_set.get(pk=request.POST[’choice’])     except (KeyError,Choice.DoesNotExist): # Redisplay the question voting form.         return render(request, ‘polls/detail.html’, { ‘question’:p, ‘error_message’: “You didn’t select a choice.”, })     else:         selected_choice.votes += 1         selected_choice.save()     #Always return an HttpResponseRedirect after successfully dealing    # with POST data. This prevents data from being posted twice if a    # user hits the Back button.         return HttpResponseRedirect(reverse(‘polls:results’, args=(p.id,)))

• request.POST是一个字典。通过key获得提交值。
• request.POST如果键值不存在会抛出异常。以上代码捕获异常。
• 每次POST成功都要redirect，使用HttpResponseRedirect()函数
• reverse()逆向调用全局视图函数

使用通用视图

1.修改URLconfs

from django.conf.urls import urlfrom . import viewsurlpatterns = [ url(r’^$’, views.IndexView.as_view(), name=’index’), url(r’^(?P<pk>[0-9]+)/$’,views.DetailView.as_view(), name=’detail’), url(r’^(?P<pk>[0-9]+)/results/$’,views.ResultsView.as_view(),name=’results’), url(r’^(?P<question_id>[0-9]+)/vote/$’, views.vote, name=’vote’),]

2.修改视图函数