使用django2映射URL遇到的问题

参考：https://blog.csdn.net/weixin_40841752/article/details/79335345

在学习《Python编程：从入门到实践》18.3.1 映射URL，遇到下面的问题：原著里使用的是1.x版本的django，本人使用的是2.1.7版本的django。而include()在1.x和2.x版本里使用方式是有区别的，照搬书上的代码，在执行python3 manage.py runserver可能会遇到下面的错误。另外2.x版本里推荐使用path替代url。

django.core.exceptions.ImproperlyConfigured:
Passing a 3-tuple to include() is not supported.
Pass a 2-tuple containing the list of patterns and app_name,
and provide the namespace argument to include() instead.
传递一个3元组给include()是不支持的。
传递一个2元组（包含patterns和app_name的列表），
并且提供namespace实参给include()替代。

django.core.exceptions.ImproperlyConfigured:
Specifying a namespace in include() without providing an app_name is not supported.
Set the app_name attribute in the included module,
or pass a 2-tuple containing the list of patterns and app_name instead.
在include方法里面指定namespace却不提供app_name是不支持的。
在包含的模块里设置app_name变量，
或者在include方法里面提供app_name参数。

原文中的代码

• learning_log/urls.py

from django.conf.urls import url, include
from django.contrib import admin

urlpatterns = [
	url(r'^admin/', include(admin.site.urls)),
	url(r'', include('learning_logs.urls',namespace='learning_logs')),
]

• learning_logs/urls.py

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

urlpatterns = [
    url(r'^$', views.index, name='index'),
]

修改后的代码

• learning_log/urls.py

from django.conf.urls import url, include
#from django.urls import path, include
from django.contrib import admin

urlpatterns = [
	url(r'^admin/', admin.site.urls),
	#path('admin/', admin.site.urls),
	url(r'', include(('learning_logs.urls', 'LL'), namespace='learning_logs')),
	#path('', include(('learning_logs.urls', 'LL'), namespace='learning_logs')),
]

• learning_logs/urls.py

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

urlpatterns = [
    url(r'^$', views.index, name='index'),
    #path('', views.index, name='index'),
]

修改说明

• #注释的是2.x版本的path的写法替换url写法。
• 当指定namespace时，必须提供app_name，这里将’LL’作为app_name

另外一种添加app_name的方式

• learning_log/urls.py

from django.conf.urls import url, include
#from django.urls import path, include
from django.contrib import admin

urlpatterns = [
	url(r'^admin/', admin.site.urls),
	#path('admin/', admin.site.urls),
	url(r'', include('learning_logs.urls', namespace='learning_logs')),
	#path('', include('learning_logs.urls', namespace='learning_logs')),
]

• learning_logs/urls.py

from django.conf.urls import url
#from django.urls import path
from . import views
app_name='LL'

urlpatterns = [
    url(r'^$', views.index, name='index'),
    #path('', views.index, name='index'),
]