Python中Django框架开发web

采用idea工具进行开发：1.Django的基本知识点：Django是Python语言中最具有代表性的一种开发web的框架；Django是一个开发源代码的web应用框架，由Python写成；Django采用MVC软件设计模式，即：模型，视图，控制器。2.Django的优缺点：①优点：a.Django自带的ORM：每条记录都是一个对象，更方便去对象的关联，封装性能好，开发速度快；b.自助管理后台：Django中强大的admin interface，使开发者不需要写任何代码便拥有一个完整的后台管理界  面，极大的方便了开发者对代码的调试等操作；c.URL design:采用正则表达式，使用起来更加方便、简洁；d.Django的APP设计理念：app可插拔，且对系统影响不大；e.Django的错误信息提示功能：强大而又详细，极大的提高了开发者的开发效率。②缺点：a.系统紧耦合：Django本身就有很多模块的tag，模型比较固定，如果想用第三方库代替，难度很大；b.Django自带的ORM不如SQLAlchemy强大：SQLAlchemy是Python中的ORM标准，除了Django框架，其他框架都支持SQLAlchemy；c.Template功能比较弱：不能插入Python代码，要写复杂一点的逻辑需要另外用Python实现Tag或Filter;d.auth模块：Django的auth跟其他模块紧密结合，功能强，用户的数据库schema是固定，但是当多网站要求email地址唯一，而schema里的字段的值不是唯一，就会出现各种问题。3.Django中的几个核心模块：1)settings.py:Django项目的设置或配置：包括以下主要常用的内容①BASE_DIR:②INSTALLED_APPS:如果新建的应用模块，里面包括：migrations文件夹和admin.py,apps.py,models.py,tests.py,urls.py,views.py文件③TEMPLATES:④DATABASES:⑤LANGUAGE_CODE:⑥STATIC_URL:2-1)urls.py:根路径下的url配置2-2)urls.py:新应用下的url配置3)views.py:视图函数，与url模块配合使用，如上：list是views中的一个函数名字4)models.py:属于数据库模块，里面所定义的数据在被加载时，会被上传到数据库5)ModelForm:可自动生成表单，在views.py模块中使用首先导入模块：from django import forms再次新建立一个类，并继承ModelForm:(forms.ModelForm)6)ModelAdmin:自定义表单:自定义管理页面取代默认管理页面4)for   if   url等标签的使用:都在表单<form>中使用：(ps:在form表单中添加{%csrf_token%} 代码，提交表单时的认证保护){%%}:%主要用于格式化字符串代入①for：语法：{%for 变量名 in 遍历对象%} {%endfor%}{% for student in students %}<li>{{ student.name }} | {{ student.sex }} | {{ student.city }} | {{ student.born }}<a href="{% url 'student:add' student.id %}">修改</a></li>{% endfor %}②if：③url:{%url student:list%} 代表的是student模块下url.py中，命名空间name的取值from django.conf.urls import urlfrom . import viewsurlpatterns=[#url(r'^add$',views.add,name='add'),不能要url(r'^add/(?P<id>[0-9]+)/$',views.add,name='add'),url(r'^save/(?P<id>[0-9]+)/$',views.save,name='save'),url(r'^list$',views.list,name='list') #{%url student:list%}]④{{form.as_p}}:表单生成前台页面，采用以段落分割的风格案例：school项目下，建立studenf7dbt和grade两张表，并建立联系以及进行数据操作前期准备工作：   Django模块学习               http://www.runoob.com/django/django-first-app.html1.打开idea中的Terminal 后台服务，输入：pip install djange  2.新建一个idea项目，选中Python，勾选Django，给Application name去一个名字，如果有警告出现，不影响3.运行文件配置：第一种：步骤(临时性的)①打开manage.py文件，复制两句代码②打开运行编辑器，并进行编辑第二种：步骤①打开file里面的project Strusture选项②选中facets,点击Django(blog),编辑Django project root 和settings代码演示：1.school模块：1)settings.pyimport 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__))) #根目录# 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 = 'ki%-rbs4#i&zz_7#lrbps@#%%0vpi&vndes#&uyh6y6c2h9bjz'# SECURITY WARNING: don't run with debug turned on in production!DEBUG = TrueALLOWED_HOSTS = []# Application definitionINSTALLED_APPS = [ #安装应用配置'django.contrib.admin','django.contrib.auth','django.contrib.contenttypes','django.contrib.sessions','django.contrib.messages','django.contrib.staticfiles','grade.apps.GradeConfig','student.apps.StudentConfig' #新建的应用配置，再次进行安装应用配置]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 = 'school.urls'TEMPLATES = [{'BACKEND': 'django.template.backends.django.DjangoTemplates','DIRS': [BASE_DIR+"/student/tem"], #项目路径配置'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 = 'school.wsgi.application'# Database# https://docs.djangoproject.com/en/1.11/ref/settings/#databases DATABASES = { #数据库驱动配置'default': {'ENGINE': 'django.db.backends.mysql', #驱动引擎，所使用的数据库类型，，MySQL'NAME': 'school', #数据库名称'USER':'root', #数据库用户名'PASSWORD':'root', #数据库密码'PORT':'3306' #数据库端口号 MySQL默认端口号：3306}}# 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 = 'zh-hans'#默认：en-us 汉字：zh-hansTIME_ZONE = 'UTC'USE_I18N = TrueUSE_L10N = TrueUSE_TZ = True# Static files (CSS, JavaScript, Images)# https://docs.djangoproject.com/en/1.11/howto/static-files/ STATIC_URL = '/static/'2)urls.pyfrom django.conf.urls import url,includefrom django.contrib import adminimport studenturlpatterns = [url(r'^admin/', admin.site.urls),url(r'^student/', include('student.urls',namespace='student')),#根模块中包含新增模块的url,namespace是别名]2.student模块：新建student模块步骤：①Ctrl+Alt+R:打开manage.py@school②命令：startapp student 回车    建立一个student应用模块③在settings.py中的INSTALLEN_APPS中进行配置：'student.apps.StudentConfig'④在models.py中创建一个student类(ps:传到数据库时，就是一张student表)⑤编辑views.py和student/urls.py，school/urls.py等相应代码⑥manage.py@school中 命令：makemigrations student   就会生成一个0001_initial.py文件，此作用：自动导入数据⑦在manage.py@school中 命令：sqlmigrate student 0001 作用：查看生成的sql语句 ⑧manage.py@school中 命令:migtate  作用：将数据添加到数据库⑨manage.py@school中 命令：createsupetuser  作用：创建超级用户(ps:密码不能小于8位，字母加数字)1)models.pyfrom django.db import modelsfrom grade.models import grade# Create your models here.class student(models.Model):class Meta:verbose_name="学生"verbose_name_plural="学生" #复合名name=models.CharField('姓名', max_length=50)sex=models.BooleanField('性别',max_length=2)born=models.DateField('生日')city=models.CharField('城市',max_length=100)likes=models.CharField('爱好',max_length=100)grade=models.ForeignKey(grade,null=True,verbose_name="班级")2)views.pyfrom django.shortcuts import render,redirectfrom django import formsfrom django.contrib import adminfrom . import models# Create your views here.def add(request,id):if id=="0":sf=student_form() #初始化表单id="0"else:student=models.student.objects.get(id=id)sf=student_form(instance=student)return render(request,"add.html",{'form':sf,"id":id})def save(request,id):if id=="0":student=models.student()else:student=models.student.objects.get(id=id)form=student_form(request.POST,instance=student)if form.is_valid(): #验证:让表单是有效的form.save()else:return render(request,"add.html",{"form":form,"id":id})return redirect("/student/list")def list(request):#查看所有学生if request.method=='POST':students=models.student.objects.filter(name__contains=request.POST['likename'])else:students=models.student.objects.all()return render(request,"list.html",{'students':students})class student_form(forms.ModelForm): #自动生成表单born=forms.DateField(widget=admin.widgets.AdminDateWidget(),label=u'生日')#format='%Y-%m-%D:%H-%M-%s'class Meta: #绑定表单model=models.studentfields=['name','sex','city','born','likes','grade']widgets={"sex":forms.RadioSelect(choices=[('男','男'),('女','女')]),"city":forms.Select(choices=[('北京','北京'),('南京','南京'),('东京','东京'),]),"likes":forms.CheckboxSelectMultiple(choices=[('体育','体育'),('游戏','游戏'),('艺术','艺术'),])}3)urls.py

from django.conf.urls import url
from . import views
urlpatterns=[
#url(r'^add$',views.add,name='add'),不能要
url(r'^add/(?P<id>[0-9]+)/$',views.add,name='add'),
url(r'^save/(?P<id>[0-9]+)/$',views.save,name='save'),
url(r'^list$',views.list,name='list')
]

4).admin.py

from django.contrib import admin
from . import models
# Register your models here.
class student_admin(admin.ModelAdmin):
class Meta:
list_display = ('name','sex','city','born')
admin.site.register(models.student,student_admin)

5).tem文件夹(ps:与migrations文件夹同级，有两HTML文件)

①add.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>

<link rel="stylesheet" type="text/css" href="/static/admin/css/base.css" />
<link rel="stylesheet" type="text/css" href="/static/admin/css/forms.css" />

<script type="text/javascript" src="/admin/jsi18n/"></script>
<script type="text/javascript" src="/static/admin/js/core.js"></script>
<script type="text/javascript" src="/static/admin/js/vendor/jquery/jquery.js"></script>
<script type="text/javascript" src="/static/admin/js/jquery.init.js"></script>
<script type="text/javascript" src="/static/admin/js/admin/RelatedObjectLookups.js"></script>
<script type="text/javascript" src="/static/admin/js/actions.js"></script>
<script type="text/javascript" src="/static/admin/js/urlify.js"></script>
<script type="text/javascript" src="/static/admin/js/prepopulate.js"></script>
<script type="text/javascript" src="/static/admin/js/vendor/xregexp/xregexp.js"></script>
<script type="text/javascript" src="/static/admin/js/calendar.js"></script>
<script type="text/javascript" src="/static/admin/js/admin/DateTimeShortcuts.js"></script>
</head>
<body>
<form action="{% url 'student:save' id %}" method="post">
{% csrf_token %}
{{ form.as_p }}{% comment %}as_p: 表单生成前台页面采用以段落分割的风格{% endcomment %}
<input type="submit" value="保存"/>
</form>
</body>
</html>

②list.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<a href="{% url 'student:add' '0' %}">添加</a>  {% comment %} '0'必须有空格{% endcomment %}
<a href="{% url 'student:add' '0' %}">返回</a>
<form action="{% url 'student:list' %}" method="post">
{% csrf_token %}

<input type="text" name="likename" value="{{ request.POST.likename}}" />
<input type="submit" value="查询"/>

<ul>
{% for student in students %}
<li>
{{ student.name }} | {{ student.sex }} | {{ student.city }} | {{ student.born }} | {{ student.likes }} | {{ student.grade.name }}
<a href="{% url 'student:add' student.id %}">修改</a>
</li>
{% endfor %}
</ul>
</form>
</body>
</html>

6)如果数据库发生增删改查的事务是，再次执行命令 makemigrations student 就会出现一个0002_auto_..._.. .py文件

(ps:0001_initial.py文件尽量不要删除，如果删了在执行 makemigrations student 这条命令，会报一些异常或错误

例如：数据无法读入数据等等)

3.grade模块

前期准备工作与创建student模块一样，只是不需要在创建超级用户：createsuperuser

1)models.py   (ps:作用与student/models.py一样)

from django.db import models# Create your models here.class grade(models.Model):def __str__(self):return self.nameclass Meta:verbose_name='年级'#获取Django model中的字段名verbose_name_plural="年级"#name=models.CharField("年级名称：",max_length=50,null=False,unique=True)start_time=models.DateField("开班时间：")

2)admin.py (ps:作用与student/admin.py一样)

from django.contrib import adminfrom . import models# Register your models here.  register: 注册class admin_grade(admin.ModelAdmin):# 要显示的内容 (属于自定义表单：自定义管理页面取代默认管理页面)list_display = ('name','start_time')#注册管理员(注册管理员后，注册才能起效)admin.site.register(models.grade,admin_grade)

3)urls.py  (ps:作用与student/urls.py一样)

from django.conf.urls import url,includefrom django.contrib import adminimport studenturlpatterns = [url(r'^admin/', admin.site.urls),url(r'^student/', include('student.urls',namespace='student')),]