了解学习pyhton web的简单demo
1. 安装Django， 安装pyhton 自行百度
2. 执行命令创建project django-admin.py startproject mysite
3. 执行命令创建app python manage.py startapp polls
目录结构： polls/templates/polls 目录 和 polls/admin.py 都是自己手动创建的。
4. 编辑setting.py 添加app polls 同时打开admin
INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'polls',
# Uncomment the next line to enable the admin:
'django.contrib.admin',
# Uncomment the next line to enable admin documentation:
# 'django.contrib.admindocs',
)
5. 编辑setting.py 添加数据库连接信息
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
'NAME': 'polls', # Or path to database file if using sqlite3.
'USER': 'root', # Not used with sqlite3.
'PASSWORD': '123', # Not used with sqlite3.
'HOST': '', # Set to empty string for localhost. Not used with sqlite3.
'PORT': '', # Set to empty string for default. Not used with sqlite3.
}
}
6. 创建Modle模型 ：
# coding=utf-8
from django.db import models
# Create your models here.
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published')
def __unicode__(self):
return self.question_text
class Choice(models.Model):
question = models.ForeignKey(Question)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
def __unicode__(self):
return self.choice_text
7. 执行数据库同步 （ORM）自动根据model定义创建表接口 （我这里使用的mysql）
首先创建数据库
create database polls;
然后执行命令：
python manage.py syncdb
8. 检查数据库中表的创建：
use polls
show tables
9. 创建admin.py
# coding=utf-8
from django.contrib import admin
from .models import Question, Choice
# Register your models here.
class ChoiceInline(admin.TabularInline):
model = Choice
extra = 3
class QuestionAdmin(admin.ModelAdmin):
fieldsets = [
(None, {'fields': ['question_text']}),
('Date information', {'fields': ['pub_date'], 'classes': ['collapse']}),
]
inlines = [ChoiceInline]
list_display = ('question_text', 'pub_date')
admin.site.register(Choice)
admin.site.register(Question, QuestionAdmin)
10. 启动应用
python manage.py runserver
登录后台：http://127.0.0.1:8000/admin 通过Django自动的后台进行问题添加
11. 编写视图控制层
视图起着承前启后的作用，前是指前端页面，后是指后台数据库。将数据库表中的内容查询出来显示到页面上。
编写polls/views.py文件：
# coding=utf-8
from django.shortcuts import render, get_object_or_404
from django.http import HttpResponseRedirect, HttpResponse
from django.core.urlresolvers import reverse
from .models import Question, Choice
# Create your views here.
# 首页展示所有问题
def index(request):
# latest_question_list2 = Question.objects.order_by('-pub_data')[:2]
latest_question_list = Question.objects.all()
context = {'latest_question_list': latest_question_list}
return render(request, 'polls/index.html', context)
# 查看所有问题
def detail(request, question_id):
question = get_object_or_404(Question, pk=question_id)
return render(request, 'polls/detail.html', {'question': question})
# 查看投票结果
def results(request, question_id):
question = get_object_or_404(Question, pk=question_id)
return render(request, 'polls/results.html', {'question': question})
# 选择投票
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,)))
12. 配置视图展示层与逻辑控制层url映射
url是一个请求配置文件，页面中的请求转交给由哪个函数处理，由该文件决定。
首先配置polls/urls.py(该文件需要创建)
from django.conf.urls import url
from . import views
urlpatterns = [
# 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'),
]
接着，编辑mysite/urls.py文件。
from django.conf.urls import include, url
from django.contrib import admin
urlpatterns = [
url(r'^polls/', include('polls.urls', namespace="polls")),
url(r'^admin/', include(admin.site.urls)),
]
13. 创建视图模板
模板就是前端页面，用来将数据显示到web页面上。
首先创建polls/templates/polls/目录，分别在该目录下创建index.html、detail.html和results.html文件。
index.html
{% if latest_question_list %}
<ul>
{% for question in latest_question_list %}
<li><a href="{% url polls:detail question.id %}">{{ question.question_text }}</a></li>
{% endfor %}
</ul>
{% else %}
<p>No polls are available.</p>
{% endif %}
detail.html
<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>
results.html
<h1>{{ question.question_text }}</h1>
<ul>
{% for choice in question.choice_set.all %}
<li>{{ choice.choice_text }} -- {{ choice.votes }} vote{{ choice.votes|pluralize }}</li>
{% endfor %}
</ul>
<a href="{% url polls:detail question.id %}">Vote again?</a>
14. 启动web容器，访问：http://127.0.0.1:8000/polls/
