Most optimized way to delete all sessions for a specific user in Django?

If you return a QuerySet from your all_unexpired_sessions_for_user function, you could limit your database hits to two:

def all_unexpired_sessions_for_user(user):    user_sessions = []    all_sessions  = Session.objects.filter(expire_date__gte=datetime.datetime.now())    for session in all_sessions:        session_data = session.get_decoded()        if user.pk == session_data.get('_auth_user_id'):            user_sessions.append(session.pk)    return Session.objects.filter(pk__in=user_sessions)def delete_all_unexpired_sessions_for_user(user, session_to_omit=None):    session_list = all_unexpired_sessions_for_user(user)    if session_to_omit is not None:        session_list.exclude(session_key=session_to_omit.session_key)    session_list.delete()

This gives you a total of two hits to the database. Once to loop over all of the Session objects, and once to delete all of the sessions. Unfortunately, I don't know of a more direct way to filter through the sessions themselves.

Another version of a function using list comprehension that will just straight up delete every unexpired session of a user:

from django.utils import timezonefrom django.contrib.sessions.models import Sessiondef delete_all_unexpired_sessions_for_user(user):    unexpired_sessions = Session.objects.filter(expire_date__gte=timezone.now())    [        session.delete() for session in unexpired_sessions        if str(user.pk) == session.get_decoded().get('_auth_user_id')    ]

The most efficient way is to store the session id of the user during login. You can access the session ID using request.session._session_key and store it in a separate model which has reference to the user. Now when you want to remove all the sessions of the user, just query this model which will return all the active sessions for the user in question. Now you need to delete only these sessions from the session table. Much better than having to look up all the sessions to filter out just sessions for a particular user.