第十六篇：django基础

本篇内容

1. 创建程序
2. 程序目录
3. 流程介绍
4. login实例

一、创建程序

命令行： django-admin startproject sitename。

常用命令：

python manage.py runserver                       # 启动程序

python manage.py startapp appname                # 新建一个项目

python manage.py syncdb

python manage.py makemigrations                  # 把数据库类转换为原生SQL语句

python manage.py migrate                         # 执行SQL语句

二、程序目录

manage.py               # 命令文件

templates               # 存放静态文件的目录

urls.py                 # URL引导

settings.py             # 主配置文件

models.py               # 创建数据库文件

views.py                # 主程序文件

admin.py                # 后台管理文件

三、流程介绍

MVC是众所周知的模式，即：将应用程序分解成三个组成部分:model(模型),view(视图),和 controller(控制 器)。其中：

　　M 管理应用程序的状态（通常存储到数据库中），并约束改变状态的行为（或者叫做“业务规则”）。

　　C 接受外部用户的操作，根据操作访问模型获取数据，并调用“视图”显示这些数据。控制器是将“模型”和“视图”隔离，并成为二者之间的联系纽带。

　　V 负责把数据格式化后呈现给用户。

Django也是一个MVC框架。但是在Django中，控制器接受用户输入的部分由框架自行处理，所以 Django 里更关注的是模型（Model）、模板(Template)和视图（Views），称为 MTV模式：

　　M 代表模型（Model），即数据存取层。 该层处理与数据相关的所有事务： 如何存取、如何验证有效性、包含哪些行为以及数据之间的关系等。

　　T 代表模板(Template)，即表现层。 该层处理与表现相关的决定： 如何在页面或其他类型文档中进行显示。

　　V 代表视图（View），即业务逻辑层。 该层包含存取模型及调取恰当模板的相关逻辑。 你可以把它看作模型与模板之间的桥梁。

四、login实例

setting.py

"""
Django settings for untitled project.

Generated by 'django-admin startproject' using Django 1.11.7.

For more information on this file, see
https://docs.djangoproject.com/en/1.11/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.11/ref/settings/
"""

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.11/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'uh2=k)l9z4!i1yvyp0a*f_&x(zcby&y^6s0dt41olgpj+n_mxo'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'app01.apps.App01Config',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    # 'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'untitled.urls'

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',
            ],
        },
    },
]

WSGI_APPLICATION = 'untitled.wsgi.application'

# Database
# https://docs.djangoproject.com/en/1.11/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}

# Password validation
# https://docs.djangoproject.com/en/1.11/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

# Internationalization
# https://docs.djangoproject.com/en/1.11/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.11/howto/static-files/

STATIC_URL = '/static/'

urls.py

"""untitled URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.11/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import url
from django.contrib import admin
from app01 import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^login/', views.login),
    url(r'^valide/', views.valide),
]

views.py

from django.shortcuts import render

# Create your views here.

from django.shortcuts import render, HttpResponse, redirect

def login(request):
    return render(request, "app01/login.html")

def valide(request):
    username = request.POST.get("user")
    passwrod = request.POST.get("pwd")
    if username == "xiaolan" and passwrod == "123456":
        return HttpResponse("验证成功")
    else:
        return redirect("/login/")

login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h3>登录页面</h3>
    <form action="http://127.0.0.1:8000/valide/" method="post">
        <p>用户名：<input type="text" name="user"></p>
        <p>密码：<input type="password" name="pwd"></p>
        <input type="submit">
    </form>
</body>
</html>