python使用Django框架开发简单项目

一、

(1)使用idea生成一个python项目,安装Django框架:

pip install django==1.8.2

(2)初始化项目:

django-admin startproject xxx //xxx为项目名称

(3)初始化应用:

python manage.py startapp xxx //xxx为应用名称

(4)在settings.py中注册刚生成的应用:

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'home', //这是我们刚生成的应用
)

(5)测试项目是否可以正常启动:

python manage.py runserver IP:端口

浏览器访问如下:

 PS:Django默认使用的是sqlite3数据库,可以根据model生成数据库表,生成的文件在migrations目录下:

(1)我们先在model中写一个测试类:

from django.db import models
# Create your models here.
#学生类
class StuUser(models.Model):
    '''学生模型类'''
    #照片
    studentName = models.CharField(max_length=255)
    studentNumber = models.CharField(max_length=255)
    picture = models.CharField(max_length=255)
    phoneNumber = models.CharField(max_length=255)
    address = models.CharField(max_length=255)
    createDate = models.DateTimeField()
    updateDate = models.DateTimeField()

(2)终端运行如下指令:

python manage.py makemigrations

运行后可以发现migrations目录下多了一个0001_initial.py文件,就是我们model的迁移文件:

# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.db import models, migrations


class Migration(migrations.Migration):

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='StuUser',
            fields=[
                ('id', models.AutoField(verbose_name='ID', primary_key=True, serialize=False, auto_created=True)),
                ('studentName', models.CharField(max_length=255)),
                ('studentNumber', models.CharField(max_length=255)),
                ('picture', models.CharField(max_length=255)),
                ('phoneNumber', models.CharField(max_length=255)),
                ('address', models.CharField(max_length=255)),
                ('createDate', models.DateTimeField()),
                ('updateDate', models.DateTimeField()),
            ],
        ),
    ]

然后再运行如下指令:

 python manage.py migrate

此时就会生成一个db.sqlite3文件,这是一个小型数据库,我们需要安装一个工具才能有可视化数据库界面,由于项目使用的是mysql数据库,后续需要更改对应数据库配置,此处不过多赘述

二、django整合mysql

(1)django完成视图搭建:(注意项目结构,我使用的idea生成的项目,需要删除一层,使项目结构如下:)

 其中homework为项目,home是我们运行如下指令初始化的应用:(一定要注意)

 python manage.py startapp home

首先,我们在settings.py配置文件的TEMPLATES->DIRS中添加如下代码:(指定模板路径)

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR,'templates')],//指定模板路径
        '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',
            ],
        },
    },
]

应用中新建对应路径的文件夹做为我们的view模板渲染层,进行前后端分离的项目就不需要这些操作了

home应用中的urls.py配置路由(默认生成的home应用没有urls.py,从项目homework中复制一份):

from django.conf.urls import  url
from home import views
urlpatterns = [
url(r'^index$',views.index),#首页
]

home应用中的views.py文件中配置视图:

from django.shortcuts import render

# Create your views here.
def index(request):
    '''首页'''
    return render(request,'home/index.html')

项目的urls.py中引入应用的路由:

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

模板中新建index.html

 index.html内容:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h1>首页</h1>
</body>
</html>

然后运行

 manage.py runserver 127.0.0.1:8080

 这样一个路由就配置好了

PS:简单介绍以下Django路由的原理,如下图所示:()

自定义404页面:

settings.py修改如下配置:

DEBUG = False

ALLOWED_HOSTS = ['127.0.0.1']

templates下新建404.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h1>页面找不到</h1>
</body>
</html>

 返回JSON数据:

 views.py

from django.shortcuts import render
from home import models
from django.shortcuts import HttpResponse
import json
# Create your views here.
def index_json(request):
    result = {"password": '111', "encrypt": '222'}
    return HttpResponse(json.dumps(result))

urls.py

from django.conf.urls import  url
from home import views
urlpatterns = [
    url(r'^index$',views.index),#首页
    url(r'^index_json$',views.index_json),#首页
 ]

浏览器访问:localhost:8080/index_json

(2)配置mysql数据库(settings.py文件中修改数据库配置):

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'stu_user',//数据库名称
        'USER': 'root',
        'PASSWORD': 'root',
        'HOST': 'localhost',
        'PORT': '3306',
    }
}

项目中新建model后,可以同步数据库表,具体指令如下(此指令只能同步Django内置表):

python manage.py syncdb

  

 其中,django_migrations是记录数据库迁移log日志,使用如下命令也可实现(会将自己的app model同步到数据库 如果想要修改表结构,修改

model后执行如下指令无法同步,请查看django_migrations中的相关日志,删除对应app的日志再执行即可):

python manage.py makemigrations
python manage.py migrate

PS:一对多模型实现:

models.py

from django.db import models
# Create your models here.
#学生类
class stu_user(models.Model):
    '''学生模型类'''
    #照片
    student_name = models.CharField(max_length=255)
    student_number = models.CharField(max_length=255)
    picture = models.CharField(max_length=255)
    phone_number = models.CharField(max_length=255)
    address = models.CharField(max_length=255)
    create_date = models.DateTimeField()
    update_date = models.DateTimeField()
#教育经历类
class stu_experience(models.Model):
    '''学生模型类'''
    #照片
    user = models.ForeignKey("stu_user", to_field='id', on_delete=models.CASCADE)
    begin_date = models.DateTimeField()
    end_date = models.DateTimeField()
    school = models.CharField(max_length=255)
    level = models.IntegerField()

 

views.py中测试新增数据:

from django.shortcuts import render
from datetime import date
from home import models
# Create your views here.
def index(request):
    '''首页'''
    book = models.StuUser(
        studentName = '冯文哲'
    )
    book.save()
    return render(request,'home/index.html')

 一对多查询,并格式化时间后json输出:

models.py中定义如下类:

class DateEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj,datetime.datetime):
            return obj.strftime("%Y-%m-%d %H:%M:%S")
        else:
            return json.JSONEncoder.default(self,obj)

views.py中定义路由业务处理:

def one_to_many(request):
    print(request)
    student = models.stu_user.objects.get(id='1')
    result = []
    exp = student.stu_experience_set.all()
    for item in exp:
        result.append(model_to_dict(item))#对象转字典
    print(type(serializers.serialize('json',exp)))
    print(type(json.loads(serializers.serialize('json',exp))))
    student = model_to_dict(student)#对象转字典
    res = {'student':student,'exp':result}#字典类型
    print(type(res))
    return HttpResponse(json.dumps(res,cls=models.DateEncoder))#格式化日期,json输出
原文地址:https://www.cnblogs.com/fengwenzhee/p/15451817.html