INSTALLED_APPS = [
    'django.contrib.admin',django.contrib.authdjango.contrib.contenttypesdjango.contrib.sessionsdjango.contrib.messagesdjango.contrib.staticfilesbooknews
from django.http import HttpResponse
 django.shortcuts import render,redirect,reverse

# Create your views here.
def index(request):
    username = request.GET.get("username")
    if username is not None:
        return HttpResponse(welcome!else:
        return redirect(reverse('book:loose',kwargs={a':100,b200}))

def error(request,a,b):
    sum=a+b
    <h1>path:{}</h1>".format(request.path))

news:loose".format(request.path))

 django.urls import path
 . import views
app_name ="book"
urlpatterns = [
    path('',views.index,name=index),path(error/<int:a>/<int:b>loose
 . import views
app_name ="news"
 django.contrib import admin
 django.urls import path,include

urlpatterns =admin/book/book.urls)),1)">news/news.urls