Django2.0报错：Specifying a namespace in include() without providing an app_name is not supported.

ゝ一世哀愁。 2022-12-01 15:59 197阅读 0赞

## 本地环境 ##

*  Python: 3.6.0
 *  Django: 2.0

## 报错信息 ##

部分：

File "/Users/Documents/D-develope/DjangoDemo/TestPro/TestPro/urls.py", line 22, in <module>
        path('demo1/', include('demo1.urls', namespace='demo1')),
      File "/Users/.pyenv/versions/3.6.0/lib/python3.6/site-packages/django/urls/conf.py", line 39, in include
        'Specifying a namespace in include() without providing an app_name '
    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.

## 问题原因 ##

*  我的代码

urlpatterns = [
        path('demo1/', include('demo1.urls', namespace='demo1'),
    ]

*  查看报错信息指向"django/urls/conf.py", line 39";  
    源代码如下：

def include(arg, namespace=None):
        app_name = None
        if isinstance(arg, tuple):
            # Callable returning a namespace hint.
            try:
                urlconf_module, app_name = arg
            except ValueError:
                if namespace:
                    raise ImproperlyConfigured(
                        'Cannot override the namespace for a dynamic module that '
                        'provides a namespace.'
                    )
                raise ImproperlyConfigured(
                    'Passing a %d-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.' % len(arg)
                )
        else:
            # No namespace hint - use manually provided namespace.
            urlconf_module = arg
    
        if isinstance(urlconf_module, str):
            urlconf_module = import_module(urlconf_module)
        patterns = getattr(urlconf_module, 'urlpatterns', urlconf_module)
        app_name = getattr(urlconf_module, 'app_name', app_name)
        if namespace and not app_name:
            raise 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.',
            )
        namespace = namespace or app_name
        # Make sure the patterns can be iterated through (without this, some
        # testcases will break).
        if isinstance(patterns, (list, tuple)):
            for url_pattern in patterns:
                pattern = getattr(url_pattern, 'pattern', None)
                if isinstance(pattern, LocalePrefixPattern):
                    raise ImproperlyConfigured(
                        'Using i18n_patterns in an included URLconf is not allowed.'
                    )
        return (urlconf_module, app_name, namespace)

## 修改方案 ##

从include()函数可以看出来，这个函数有两个参数，一个arg，一个namespace，我在代码中也是两个参数，但是异常中提示了，没有提供app\_name，还提示需要传入一个两元元组，从第六行代码  
urlconf\_module, app\_name = arg 可以看出来，arg就是那个元组，且给app\_name赋值了，所以我们这里修改代码为：

urlpatterns = [
        path('demo1/', include(('demo1.urls', 'demo1'), namespace='demo1')),