无法导入LoginView？

Question

我正在学习一些关于Django 1.9的东西，我想做一个登录表单，但是要使用基于类的视图。

这是mi视图代码：

from django.shortcuts import render

from django.contrib.auth.views import LoginView

class AlumnoLoginView(LoginView):
    template_name = "alumno/login.html"
    redirect_authenticated_user = True

这是我的urls代码：

from django.conf.urls import url, include

from .views import AlumnoLoginView

app_name = 'alumno'
urlpatterns = [
    url(r'^login/$', AlumnoLoginView.as_view(), name="login"),
]

这会产生一个错误：

ImportError: cannot import name LoginView

但是如果我删除urls中的代码，什么也不会发生。

这是完整的错误跟踪(使用François更改)：

Unhandled exception in thread started by <function wrapper at 0x7f044ad8ac08>
Traceback (most recent call last):
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 116, in inner_run
    self.check(display_num_errors=True)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/management/base.py", line 426, in check
    include_deployment_checks=include_deployment_checks,
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/checks/registry.py", line 75, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/checks/urls.py", line 13, in check_url_config
    return check_resolver(resolver)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/checks/urls.py", line 23, in check_resolver
    for pattern in resolver.url_patterns:
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 417, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 410, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/plafhz/Envs/StudentAdmin/studentadmin/studentadmin/urls.py", line 21, in <module>
    url(r'^alumno/', include('alumno.urls')),
  File "/home/plafhz/Envs/StudentAdmin/local/lib/python2.7/site-packages/django/conf/urls/__init__.py", line 52, in include
    urlconf_module = import_module(urlconf_module)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/plafhz/Envs/StudentAdmin/studentadmin/alumno/urls.py", line 3, in <module>
    from alumno.views import AlumnoLoginView
  File "/home/plafhz/Envs/StudentAdmin/studentadmin/alumno/views.py", line 3, in <module>
    from django.contrib.auth.views import LoginView as BaseLoginView
ImportError: cannot import name LoginView

怎么啦？我该怎么解决它？感谢:)