Django urls.py报错: raise TypeError('view must be a callable or a list/tuple in the case of include()

"F:\PyCharm 2016.2.2\bin\runnerw.exe" C:\Users\Administrator\AppData\Local\Programs\Python\Python35\python.exe F:/Django/blogs/manage.py runserver 8000
Performing system checks...

Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x000000B2A48F4950>
Traceback (most recent call last):
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\utils\autoreload.py", line 226, in wrapper
fn(*args, **kwargs)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\management\commands\runserver.py", line 121, in inner_run
self.check(display_num_errors=True)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\management\base.py", line 374, in check
include_deployment_checks=include_deployment_checks,
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\management\base.py", line 361, in _run_checks
return checks.run_checks(**kwargs)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\checks\registry.py", line 81, in run_checks
new_errors = check(app_configs=app_configs)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\checks\urls.py", line 14, in check_url_config
return check_resolver(resolver)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\core\checks\urls.py", line 24, in check_resolver
for pattern in resolver.url_patterns:
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\utils\functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\urls\resolvers.py", line 313, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\utils\functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\urls\resolvers.py", line 306, in urlconf_module
return import_module(self.urlconf_name)
File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "F:\Django\blogs\blogs\urls.py", line 26, in <module>
url(r‘^backend/‘, include(‘backend.urls‘)),
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\conf\urls\__init__.py", line 50, in include
urlconf_module = import_module(urlconf_module)
File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 665, in exec_module
File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
File "F:\Django\blogs\backend\urls.py", line 13, in <module>
url(r‘^editarticle-(?P<nid>\d+).html$‘,user.editarticle),
File "C:\Users\Administrator\AppData\Roaming\Python\Python35\site-packages\django\conf\urls\__init__.py", line 85, in url
raise TypeError(‘view must be a callable or a list/tuple in the case of include().‘)
TypeError: view must be a callable or a list/tuple in the case of include().

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/1.10/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  url(r‘^$‘, views.home, name=‘home‘)
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  url(r‘^$‘, Home.as_view(), name=‘home‘)
Including another URLconf
    1. Import the include() function: from django.conf.urls import url, include
    2. Add a URL to urlpatterns:  url(r‘^blog/‘, include(‘blog.urls‘))