Python Web框架

本节对Python Web框架学习

一、MTV
Model: 存放所有数据库相关文件
Template：模板文件，存放html文件
View：业务处理，即函数文件

二、MVC
model: 存放数据库相关文件
view: 存放所有的html文件
controler: 存放所有的函数文件

三、Django
Django基于MTV模式的web框架
1、下载安装

https://www.djangoproject.com/download/

2、创建项目
django-admin startproject django_p01
./django_p01
　　/django_p01
　　　　__init__.py
　　　　settings.py
　　　　urls.py
　　　　wsgi.py
　　/manage.py
3、启动项目

python manage.py runserver 127.0.0.1:8000

Performing system checks...
System check identified no issues (0 silenced).
You have unapplied migrations; your app may not work properly until they are applied.
Run 'python manage.py migrate' to apply them.
December 18, 2017 - 22:42:56
Django version 1.8.17, using settings 'django_p01.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.

4、访问项目

浏览器输入：127.0.0.1:8000显示以下内容表示项目启动成功

5、项目流程

django访问流程如图：

a.创建Django工程

django-admin  startproject  django_p01
./django_p01                        ##项目名称
    /django_p01                        ##和项目同名二级目录，用于整个程序配置
                __init__.py            ##
                settings.py            ##程序配置文件
                urls.py                ##URL对应关系配置文件
                wsgi.py                ##Socket内部创建，遵循一定wsgi规则，线上UWSGI+Nginx
    /manage.py                        ##Django程序管理(python manage.py /python manage.py startapp xx/python manage.py migrate/python manage.py makemigrations)
    
manage.py——>settings——>urls——>views

b.创建app

python manage.py startapp cmdb
    admin.py            ##后台管理界面
    migrations            ##记录数据库相关变更(DDL)
    models.py            ##数据库相关文件内容，数据库字典定义,ORM
    tests.py            ##单元测试
    views.py            ##函数内容，实际操作业务逻辑代码
    __init__.py
    apps.py                ##配置当前app

新加app，需要在settings加载app名称

INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'cmdb',
)

c.静态文件路径配置

配置文件：settings.py
STATICFILES_DIR=(
os.path.join(BASE_DIR,'static'),
)

d.模板路径配置

配置文件:settings.py
TEMPLATES = [
{
'DIRS': [os.path.join(BASE_DIR, 'templates')],
},
]

e.相关内容注释

配置文件:settings.py
注释CSRF
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
# 'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'django.middleware.security.SecurityMiddleware',
)

f.定义路由规则

需要在urls.py中导入相应应用模块（from cmdb import views），然后在urls.py中建立索引、函数对应关系

配置文件：urls.py
from cmdb import views
urlpatterns = [
url(r'^admin/', include(admin.site.urls)),
url(r'^login/',views.login)
]

g.定义视图函数

配置文件:views.py
from django.shortcuts import render
from django.shortcuts import redirect
from django.shortcuts import HttpResponse
# Create your views here.

def login(request):
if request.method=='POST':
user=request.POST['user']
password=request.POST['password']
if user=='tom' and password=='123456':
return redirect('http://www.baidu.com')
else:
return render(request,'login.html')

##request.method有两种获取请求数据的方式：get/post
request.GET.get('',None)    ##获取请求发送来的数据
request.POST.get('',None)    ##获取请求发送来的数据
##返回请求数据的方式
return HttpResponse("字符串")
return    render(request,"HTML模板路径")
return    redirect("URL")    ##本地URL需要加/URL名称

h.模板渲染

函数内容：
return render(request,'login.html',{'username':"tom",list=[1,2,3]})
模板内容：
{{变量名}}
{{dict.k1}}
{% for row in user_list%}
xxx
{% endfor %}
{{% if true %}}
xxx
{{%    else %}}
xxx
{{ endif }}

6、其他说明

a.settings.py内容说明

"""
Django settings for django_p01 project.

Generated by 'django-admin startproject' using Django 1.8.17.

For more information on this file, see
https://docs.djangoproject.com/en/1.8/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.8/ref/settings/
"""

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
import os

##项目基目录

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/1.8/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '#(scd$4xhwyv35o37-ud)5+ctz_629-afv9u42==_n7f^+&#7^'

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

ALLOWED_HOSTS = []


# Application definition APP列表

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'cmdb',
)

MIDDLEWARE_CLASSES = (
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    # 'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.security.SecurityMiddleware',
)

##URLS根目录


ROOT_URLCONF = 'django_p01.urls'

##templates路径

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 = 'django_p01.wsgi.application'


# Database
# https://docs.djangoproject.com/en/1.8/ref/settings/#databases

##数据源配置

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


# Internationalization
# https://docs.djangoproject.com/en/1.8/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/1.8/howto/static-files/
##静态文件路径，js/css等
STATIC_URL = '/static/'

STATICFILES_DIR=(
os.path.join(BASE_DIR,'static'),
)

b.urls.py内容说明

主要配置函数、视图映射关系

"""django_p01 URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.8/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. Add a URL to urlpatterns:  url(r'^blog/', include('blog.urls'))
"""
from django.conf.urls import include, url
from django.contrib import admin
from cmdb import views　　　　##需导入项目函数文件名称

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

c.views.py内容说明

from django.shortcuts import render
from django.shortcuts import redirect
from django.shortcuts import HttpResponse
# Create your views here.

def login(request):
    if request.method=='POST':
        user=request.POST['user']
        password=request.POST['password']
        if user=='tom' and password=='123456':
            return redirect('http://www.baidu.com')
        else:
            return render(request,'login.html')