Django获取不到特定链接

python日常踩坑系列

按照教程方式打开本地特定链接报错
源码如下：

from django.conf.urls import url
from . import views

urlpatterns = [
    # Home page.
    url(r'^$', views.index, name='index'),
    
    # Show all topics.
    url(r'^topics/$', views.topics, name='topics'),
    
    # Detail page for a single topic.
    url(r'^topics/(?P<topic_id>\d+)/$', views.topic, name='topic'),
]

打开http://127.0.0.1:8000/topics/1/报错：

 Using the URLconf defined in learning_log.urls, Django tried these URL patterns, in this order:
  1. admin/
  2. [name='index']
  3. topics [name='topics']
  4. topics/?P<topic_id>\d+/ [name='topic']
The current path, topics/1/, didn't match any of these.

原因：

Django2.0有更新
对于django.urls.path()函数，允许有简单的表示方法：

url(r’^articles/(?P[0-9]{4})/$’, views.year_archive),

可以写成：

path(‘articles/int:year/‘, views.year_archive),

所以代码可更改为：

from django.urls import path
from . import views

app_name = 'lerning_logs'
urlpatterns = [
    #主页
    path('', views.index, name='index'),
    #显示所有主题
    path('topics', views.topics, name='topics'),
    #特定主题的详细页面
    #path('topics/?P<topic_id>\d+/', views.topic, name='topic'),
    path('topics/<topic_id>/', views.topic, name='topic'),
]