3.6 Add namespace for URL

first_django_app.md

@@ -240,3 +240,10 @@ Consider `index.html` will be reused numerous times, 去耦合is necessary.
 ```html
 <li><a href="{% url 'detail' question.id %}">{{ question.question_text }}</a></li>
 ```
+
+### 3.6 为 URL 名称添加命名空间
+
+在根 URLconf 中添加命名空间 (namespace)
+
+1. Add `app_name = 'polls'` for namespace in `poll.urls.py`
+2. Change `detail` in `index.html` to `polls:detail`

src/polls/templates/polls/index.html

@@ -1,7 +1,7 @@
 {% if latest_question_list %}
     <ul>
     {% for question in latest_question_list %}
-        <li><a href="{% url 'detail' question.id %}">{{ question.question_text }}</a></li>
+        <li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>
     {% endfor %}
     </ul>
 {% else %}

src/polls/urls.py

@@ -2,6 +2,7 @@ from django.urls import path
 
 from . import views
 
+app_name = 'polls'
 urlpatterns = [
     # ex: /polls/
     path('', views.index, name='index'),