r"""

>>> from django.conf import settings

>>> from django.contrib.sessions.backends.db import SessionStore as DatabaseSession

>>> from django.contrib.sessions.backends.cache import SessionStore as CacheSession

>>> from django.contrib.sessions.backends.file import SessionStore as FileSession

>>> from django.contrib.sessions.backends.base import SessionBase

>>> db_session = DatabaseSession()

>>> db_session.modified

False

>>> db_session['cat'] = "dog"

>>> db_session.modified

True

>>> db_session.pop('cat')

'dog'

>>> db_session.pop('some key', 'does not exist')

'does not exist'

>>> db_session.save()

>>> db_session.exists(db_session.session_key)

True

>>> db_session.delete(db_session.session_key)

>>> db_session.exists(db_session.session_key)

False

>>> file_session = FileSession()

>>> file_session.modified

False

>>> file_session['cat'] = "dog"

>>> file_session.modified

True

>>> file_session.pop('cat')

'dog'

>>> file_session.pop('some key', 'does not exist')

'does not exist'

>>> file_session.save()

>>> file_session.exists(file_session.session_key)

True

>>> file_session.delete(file_session.session_key)

>>> file_session.exists(file_session.session_key)

False

# Make sure the file backend checks for a good storage dir

>>> settings.SESSION_FILE_PATH = "/if/this/directory/exists/you/have/a/weird/computer"

>>> FileSession()

Traceback (innermost last):

    ...

ImproperlyConfigured: The session storage path '/if/this/directory/exists/you/have/a/weird/computer' doesn't exist. Please set your SESSION_FILE_PATH setting to an existing directory in which Django can store session data.

>>> cache_session = CacheSession()

>>> cache_session.modified

False

>>> cache_session['cat'] = "dog"

>>> cache_session.modified

True

>>> cache_session.pop('cat')

'dog'

>>> cache_session.pop('some key', 'does not exist')

'does not exist'

>>> cache_session.save()

>>> cache_session.delete(cache_session.session_key)

>>> cache_session.exists(cache_session.session_key)

False

>>> s = SessionBase()

>>> s._session['some key'] = 'exists' # Pre-populate the session with some data

>>> s.accessed = False   # Reset to pretend this wasn't accessed previously

>>> s.accessed, s.modified

(False, False)

>>> s.pop('non existant key', 'does not exist')

'does not exist'

>>> s.accessed, s.modified

(True, False)

>>> s.setdefault('foo', 'bar')

'bar'

>>> s.setdefault('foo', 'baz')

'bar'

>>> s.accessed = False  # Reset the accessed flag

>>> s.pop('some key')

'exists'

>>> s.accessed, s.modified

(True, True)

>>> s.pop('some key', 'does not exist')

'does not exist'

"""

if __name__ == '__main__':

    import doctest

    doctest.testmod()