昨天装了一个locustio 0.14.5，依赖的django1.10升级到了django3.0，结果启动:python3 manage.py runserver

报错：

django 1.10

url(r'^api/', include('sign.urls',namespace="sign")

raise ImproperlyConfigured(msg.format(name=self.urlconf_name))
django.core.exceptions.ImproperlyConfigured: The included URLconf 'guest2.urls' does not appear to have any patterns in it.
If you see valid patterns in the file then the issue is probably caused by a circular import.

解决方式：

django 3.0.4

url(r'^api/', include('sign.urls'))