How efficient is Django Core Pagination?

I have a query set of some 500 objects... which I get after running the initial query set in some loops and checking a few conditions and excluding the objects that do not meet the criteria... and I am displaying these objects using Django core pagination.. how efficient is this and if not, what are the alternatives.

EDIT: this code probably does not make sense. but this is how I am filtering the initial query set

projs = Model.objects.filter(user=user)

    if request.user.is_authenticated:
        for x in projs:
            if x.restrictions: # restrictions is a string
                split = x.restrictions.split(',')
                for word in split:
                    checking = re.findall("@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+", request.user.username)[0]
                    if word == checking or word == request.user.username:                 
                        break
                    else:
                        projs = projs.exclude(id=x.id)
    else:
        for x in projs:
            if x.restrictions:
                projs = projs.exclude(id=x.id)