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-8from 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_textclass 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-8from django.contrib import adminfrom .models import Question, Choice# Register your models here.class ChoiceInline(admin.TabularInline):    model = Choice    extra = 3class 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： 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-8from django.shortcuts import render, get_object_or_404from django.http import HttpResponseRedirect, HttpResponsefrom django.core.urlresolvers import reversefrom .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 urlfrom . import viewsurlpatterns = [    # ex : /polls/    url(r'^$', views.index, name='index'),    # ex : /polls/5/    url(r'^(?P
     
      [0-9]+)/$', views.detail, name='detail'),    # ex : /polls/5/results/    url(r'^(?P
      
       [0-9]+)/results/$', views.results, name='results'),    # ex : /polls/5/vote    url(r'^(?P
       
        [0-9]+)/vote/$', views.vote, name='vote'),]
       
      
     

　　

接着，编辑mysite/urls.py文件。

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)),]

　　

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 %}    
     
          {% for question in latest_question_list %}        
      
{
    { question.question_text }}
    {% endfor %}    
     
{% else %}    
No polls are available.
{% endif %}

　　

detail.html

{
    { question.question_text }}
{% if error_message %}
{
    { error_message }}
{% endif %}
     
      {% csrf_token %}{% for choice in question.choice_set.all %}    
          
      {
    { choice.choice_text }}
      
{% endfor %}
      
     

　　

results.html

{
    { question.question_text }}
     
      {% for choice in question.choice_set.all %}    
      
{
    { choice.choice_text }} -- {
    { choice.votes }} vote{
    { choice.votes|pluralize }}
{% endfor %}
     
Vote again?

　　

14. 启动web容器，访问：