python 后端 django简单入门及应用实例

python django

install django

pip3 install django

link django

sudo ln -is /Library/Frameworks/Python.framework/Versions/3.10/bin/django-admin /usr/local/bin/django-admin

create django

django-admin startproject projectname

create app

python3 manage.py startapp app 

• 修改app下面的文件

• 增加static 放置静态文件

• 增加templates放置模版

  • 增加main.html

• views.py增加请求地址

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'app',  # install app
]

def home(request):
    return render(request,'main.html')

• 修改urls.py

"""demo URL Configuration

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/4.1/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path

from app.views import home

urlpatterns = [
    path('admin/', admin.site.urls),
    path('',home,name='home'),
]

python3 manage.py runserver 8081

安装数据库

sudo pip3 install pymysql

配置数据库

DATABASES = {
    
    
    'default': {
    
    
        #'ENGINE': 'django.db.backends.sqlite3',
        #'NAME': BASE_DIR / 'db.sqlite3',
        'ENGINE':'django.db.backends.mysql',
        'NAME':'demodb',
        'HOST':'127.0.0.1',
        'PORT':'3306',
        'USER':'root',
        'PASSWORD':'123456',
    }
}

创建数据表

数据迁移

python manage.py makemigrations

migrate

python manage.py migrate

from django.db import connection
from django.shortcuts import render

import json

# Create your views here.
from app.models import MyInfo


def home(request):
    data_center = get_all() # getDataBySql_center() # getdata_center()
    context = {
    
    
        'data_center': data_center
    }
    return render(request, 'main.html', context)

def load_json(request):
    with open(r'D:\practice\demo\app\static\data.json', encoding='utf-8') as f:
        data = json.load(f)
        info = data['RECORDS']
        for re_data in info:
            record = MyInfo(
                confirmedCount=re_data['confirmedCount'],
                confirmedIncr=re_data['confirmedIncr'],
                curedCount=re_data['curedCount'],
                curedIncr=re_data['curedIncr'],
                currentConfirmedCount=re_data['currentConfirmedCount'],
                currentConfirmedIncr=re_data['currentConfirmedIncr'],
                dateId=re_data['dateId'][:4]+'-'+re_data['dateId'][4:6]+'-'+re_data['dateId'][6:8],
                deadCount=re_data['deadCount'],
                deadIncr=re_data['deadIncr'],
                suspectedCount=re_data['suspectedCount'],
                suspectedCountIncr=re_data['suspectedCountIncr'],
                provinceName=re_data['provinceName'],
                provinceShortName=re_data['provinceShortName']
            )
            record.save()
    return render(request,'200.html')

# get province data

def getdata_center():
    maxdate = MyInfo.objects.latest('dateId').dateId
    result = MyInfo.objects.filter(dateId=maxdate)
    list = [] # add current increase num and province data
    for info in result:
        pInfo = {
    
    }
        pInfo['name'] = info.provinceShortName
        pInfo['value'] = info.confirmedIncr
        list.append(pInfo)
    return list

def getDataBySql_center():
    cursor = connection.cursor()
    sql = 'select provinceShortName,confirmedCount,dateId from app_myinfo where ' \
          'dateId in (select max(dateId) as datetidnew from app_myinfo)'
    cursor.execute(sql)
    result = cursor.fetchall()
    cursor.close()
    connection.close()
    list = [] # add current increase num and province data
    for info in result:
        pInfo = {
    
    }
        pInfo['name'] = info[0]
        pInfo['value'] = info[1]
        list.append(pInfo)
    return list

def get_all():
    result = MyInfo.objects.all()
    list = []
    for info in result:
        pInfo = {
    
    }
        pInfo['name'] = info.provinceShortName
        pInfo['value'] = info.confirmedIncr
        list.append(pInfo)
    return result

参考链接

https://www.runoob.com/django/django-install.html