from django.conf.urls import url
from app02 import views
urlpatterns = [
  url(r'^blog/', views.test, name="blog"),
]

from django.conf.urls import url
from app01 import views
urlpatterns = [
  url(r'^blog/', views.blog, name="blog"),
]

from django.shortcuts import render
def test(request):
  return render(request, "test.html") 
 def blog(request):
  return render(request, "news/blog.html") # news 前不要加 /

from django.shortcuts import render 
def test(request):
  return render(request, "books/blog.html") # books 前不要加 /

from django.conf.urls import url, include
from app01 import views
from app01 import urls as app01_urls
from app02 import urls as app02_urls
urlpatterns = [
  url(r'^test/', views.test),
  url(r'^blog/', include(app01_urls, namespace="news")),
  url(r'^blog/', include(app02_urls, namespace="books")),
]

<a href="{% url 'books:blog' %}" rel="external nofollow" >书籍</a>
<a href="{% url 'news:blog' %}" rel="external nofollow" >新闻</a>