Django 2.1.2创建一个项目：
django-admin startproject learnings
Django 2.1.2项目中创建一个应用：
1.新建一个应用(app), 名称叫 learn
python manage.py startapp learn # learn 是一个app的名称
2.在learn应用中修改视图文件views.py：
# Create your views here.
from django.http import HttpResponse
def index(request):
return HttpResponse(u"欢迎光临 自强学堂!")
3.把我们新定义的app加到settings.py中的INSTALL_APPS中：
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'learn',
4. Django 2.0 版本后，urls.py
from django.contrib import admin
from django.urls import path
import learn.views
urlpatterns = [
path('', learn.views.index),
path('admin/', admin.site.urls),
]
运行：
python manage.py runserver 0.0.0.0:8000
