美文网首页
Python爬虫实战笔记_4-1 Django Entrance

Python爬虫实战笔记_4-1 Django Entrance

作者: Sugeei | 来源:发表于2016-07-20 22:28 被阅读111次
    Step by step, my first django app
    1. Django startproject.
    $ django-admin startproject mysite
    
    1. Django startapp.
    $ cd mysite
    $ python3 manage.py startapp myapp ### 环境中2.7与3.5版本并存,这里需要指明python3
    
    1. Go to pycharm, find settings.py, add app name 'myapp' into INSTALLED_APPS list.
    INSTALLED_APPS = [
        'django.contrib.admin',
        'django.contrib.auth',
        'django.contrib.contenttypes',
        'django.contrib.sessions',
        'django.contrib.messages',
        'django.contrib.staticfiles',
        'myapp',  ###
    ]
    
    1. Create a new directory 'templates'(与manage.py同级), and add this directory into settings.py.
      If 'APP_DIRS' is True,It tells Django engine that you should look for templates inside installed applications besides the base DIR. If False, then the engine only search mysite/templates.
    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',
                ],
            },
        },
    ]
    
    1. New a file 'index.html' under 'templates'. Design it.
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <div class="header">
            Welcome Django!
        </div>
        <div class="footer">
            <p></p>
        </div>
    </body>
    </html>
    
    1. In views.py, define a function. It will return a rendered html
    def menublog(request):
            return render(request, 'index.html')
    
    1. Go to urls.py, define the url to lead all urls beginning with 'index' to 'menublog' defined in vews.py
    from myapp.views import menublog
    urlpatterns = [
        url(r'^admin/', admin.site.urls),
        url(r'^index/', menublog)
    ]
    
    1. python manage.py runserver
    python3 manage.py migrate
    python3 manage.py runserver localhost:9001
    
    1. visit 'http://localhost:9001/index/' and 'Welcome Django!' will show on your browser.

    Congratulations!

    关联templates与静态资源如CSS, img
    1. settings.py中添加静态资源的路径
    STATICFILES_DIRS = (os.path.join(BASE_DIR, "static"),)
    
    1. 新建一个与manage.py同级的目录名称为"static"
      此目录下存放CSS, img等资源。

    2. 在templates 中引用静态资源
      index.html的第一行添加如下语法加载静态资源,同时将资源的引用路径都替换为src="{% static 'images/0001.jpg' %}"类似的格式。

    {% load static %}
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>The blah</title>
        <link rel="stylesheet" type="text/css" href="{% static 'css/homework.css' %}">
    </head>
    <body>
        <div class="header">
            ![]({% static 'images/blah.png' %})
            <ul class="nav">
                <li><a href="#" >home</a></li>
                <li><a href="#" >site</a></li>
                <li><a href="#" >other</a></li>
            </ul>
        </div>
        <div class="main-content">
            <h2>The Beach</h2>
            <hr>
            <ul class="photos">
                <li>
                    ![]({% static 'images/0001.jpg' %})
                </li>
                <li>
                    ![]({% static 'images/0004.jpg' %})
                </li>
                <li>
                    ![]({% static 'images/0003.jpg' %})
                </li>
            </ul>
            <p>
                stretching from Solta to M1jets
            </p>
        </div>
        <div class="footer">
            <p>© Mugglecoding</p>
        </div>
    </body>
    </html>
    
    Connect model

    这一步实现从数据库中获取数据并填充到templates的指定位置。

    1. pip install mongoengine
    2. in setting.py, connect your model
    # website是目标数据库的名字
    from mongoengine import connect
    connect('website', host='127.0.0.1', port=27017)
    
    1. go to models.py to define your own model
    from django.db import models
    from mongoengine import *
    #  Create your models here.
    class menublog(Document):
          des = StringField()
          title = StringField()
          score = StringField()
          tags = ListField(StringField())
          author = StringField()
          # targettable 指定数据库website中的一张数据表的名字
          meta = {
            'collection': 'targettable'
        }
    
    1. in views.py, import your model
      render() combines a given template with a given context dictionary and returns an HttpResponse object with that rendered text.
    # 导入models.py中定义的class menublog
    from myapp.models import menublog
    def myview(request):
          data = menublog.objects
          # mydata将作为key在templates中被引用
          context = {    
             'mydata': data}
          return render(request, 'index.html', context)
    
    1. Django template language
      引用views.py中myview返回的HttpResponse
    ......
               {% for item in mydata %}
                    <li>
                        ![]({% static 'images/0001.jpg' %})
                        <div class="article-info">
                            <h3><a href="#">{{ item.title }}</a></h3>
                            <p class="meta-info">
                                {% for tag in item.tags %}
                                    <span class="meta-cate">{{ tag }}</span>
                                {% endfor %}
                            </p>
                            <p class="description">{{ item.des }}</p>
                        </div>
                        <div class="rate">
                            <span class="rate-score">{{ item.score }}</span>
                        </div>
                    </li>
               {% endfor %}
    ......
    

    就像直接使用python一样,for循环也可以嵌套。

    至此,对Django的整个框架结构有了初步的印象。
    Keep going...

    相关文章

      网友评论

          本文标题:Python爬虫实战笔记_4-1 Django Entrance

          本文链接:https://www.haomeiwen.com/subject/lxpdjttx.html