Django project is looking for "_session_cache" attribute
So, I have a Django project that doesn't use a database (the DATABASES parameter is commented out). I decided to use Django as there is a chance that I will need database features in the future. Anyway, I've been working on this project and shutting it down for a couple of months with no problem. I am using Linux Mint and have no problem using the command so far python manage.py runserver
.
Well, today I launched the application and started the local server with no problem. Then I tried to open the application in my browser and got a rather disgusting error message:
Traceback (most recent call last):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 170, in _get_session
return self._session_cache
AttributeError: 'SessionStore' object has no attribute '_session_cache'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/core/handlers/base.py", line 87, in get_response
response = middleware_method(request)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/middleware.py", line 34, in process_request
if user and hasattr(user, 'get_session_auth_hash'):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/utils/functional.py", line 224, in inner
self._setup()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/utils/functional.py", line 357, in _setup
self._wrapped = self._setupfunc()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/middleware.py", line 23, in <lambda>
request.user = SimpleLazyObject(lambda: get_user(request))
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/middleware.py", line 11, in get_user
request._cached_user = auth.get_user(request)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/__init__.py", line 151, in get_user
user_id = request.session[SESSION_KEY]
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 49, in __getitem__
return self._session[key]
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 175, in _get_session
self._session_cache = self.load()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/db.py", line 21, in load
expire_date__gt=timezone.now()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/manager.py", line 92, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 351, in get
num = len(clone)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 122, in __len__
self._fetch_all()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 966, in _fetch_all
self._result_cache = list(self.iterator())
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 265, in iterator
for row in compiler.results_iter():
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 700, in results_iter
for rows in self.execute_sql(MULTI):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 775, in execute_sql
sql, params = self.as_sql()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 100, in as_sql
out_cols, s_params = self.get_columns(with_col_aliases)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 246, in get_columns
col_aliases)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 328, in get_default_columns
r = '%s.%s' % (qn(alias), qn2(column))
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 62, in __call__
r = self.connection.ops.quote_name(name)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/backends/dummy/base.py", line 18, in complain
raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 170, in _get_session
return self._session_cache
AttributeError: 'SessionStore' object has no attribute '_session_cache'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.3/wsgiref/handlers.py", line 137, in run
self.result = application(self.environ, self.start_response)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/staticfiles/handlers.py", line 64, in __call__
return self.application(environ, start_response)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/core/handlers/wsgi.py", line 187, in __call__
response = self.get_response(request)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/core/handlers/base.py", line 199, in get_response
response = self.handle_uncaught_exception(request, resolver, sys.exc_info())
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/core/handlers/base.py", line 236, in handle_uncaught_exception
return debug.technical_500_response(request, *exc_info)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 91, in technical_500_response
html = reporter.get_traceback_html()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 349, in get_traceback_html
c = Context(self.get_traceback_data(), use_l10n=False)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 307, in get_traceback_data
frames = self.get_traceback_frames()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 465, in get_traceback_frames
'vars': self.filter.get_traceback_frame_variables(self.request, tb.tb_frame),
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 232, in get_traceback_frame_variables
cleansed[name] = self.cleanse_special_types(request, value)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/views/debug.py", line 187, in cleanse_special_types
if isinstance(value, HttpRequest):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/utils/functional.py", line 224, in inner
self._setup()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/utils/functional.py", line 357, in _setup
self._wrapped = self._setupfunc()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/middleware.py", line 23, in <lambda>
request.user = SimpleLazyObject(lambda: get_user(request))
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/middleware.py", line 11, in get_user
request._cached_user = auth.get_user(request)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/auth/__init__.py", line 151, in get_user
user_id = request.session[SESSION_KEY]
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 49, in __getitem__
return self._session[key]
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/base.py", line 175, in _get_session
self._session_cache = self.load()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/contrib/sessions/backends/db.py", line 21, in load
expire_date__gt=timezone.now()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/manager.py", line 92, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 351, in get
num = len(clone)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 122, in __len__
self._fetch_all()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 966, in _fetch_all
self._result_cache = list(self.iterator())
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/query.py", line 265, in iterator
for row in compiler.results_iter():
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 700, in results_iter
for rows in self.execute_sql(MULTI):
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 775, in execute_sql
sql, params = self.as_sql()
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 100, in as_sql
out_cols, s_params = self.get_columns(with_col_aliases)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 246, in get_columns
col_aliases)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 328, in get_default_columns
r = '%s.%s' % (qn(alias), qn2(column))
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/models/sql/compiler.py", line 62, in __call__
r = self.connection.ops.quote_name(name)
File "/home/peter/.virtualenvs/vis_it/lib/python3.3/site-packages/django/db/backends/dummy/base.py", line 18, in complain
raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.
[28/Nov/2014 13:18:54] "GET / HTTP/1.1" 500 59
I haven't touched the app since the last time I worked on it and it worked fine then. I really have no idea what this is about since I have no caches implemented and I am not using a database ... I asked a few colleges that are familiar with Django and have no idea what it is. Any ideas? I also tried setting DATABASES to an empty dict {} as recommended by a post on the net, but to no avail. In some confusion.
EDIT: I think I should mention that in the interval since I last touched this project, I have since started and set up a new Django project that uses a database. Is it possible that this project is somehow cached and breaks the one I'm currently trying to work on?
EDIT 2: I should note that this web app is currently up and running at http://mrcagney-maps.com . The code is exactly the same (haven't touched it since I last posted to the server). Very strange.
+6
source to share
2 answers
The error AttributeError: 'SessionStore' object has no attribute '_session_cache'
can come from a database that does not have a django_session table. However, since you are not using a table, you need to make sure that you do not have 'django.contrib.sessions.middleware.SessionMiddleware'
to MIDDLEWARE_CLASSES in the project configuration file. If it's there, it will look for the database table that stores the sessions, resulting in the above error.
+4
source to share
Here's what worked for me. Since there are no databases in your application. The admin page looks for the default database. So first, let's create the default databases.
Shut down your servers and start
python manage.py makemigrations
python manage.py migrate
Now create an administrator or superuser for your application. Enter your username and password.
python manage.py createsuperuser
Now reboot the server and go to the admin page
python manage.py runserver
0
source to share