django路由跳转顺序：
1.用户输入路径
www.xxxxx.com/testappfunction
2.项目主目录urls的urlpatterns里去寻找有没有匹配路径，或有没有include到其他app二级跳转
urlpatterns = [
path('admin/', admin.site.urls),
path('testappfunction/', include('testappfunction.urls'))
]
3.最终找到后，读取urlpatterns的path里的views.func
urlpatterns = [
path('', views.index, name='index'),
]
4.读取views.py里的func中返回的html页面
def index(request):
# render渲染，表示返回渲染的网页blog_index.html
return render(request, 'testappfunction_index.html')
