python - Django getting objects from a mixin -

i have small model method i'm using previous , next object relative current object. looks this:

class article     ...     def get_prev_next(self):         articles = list(article.objects.all())         = articles.index(self)         try:             p = articles[i - 1]         except indexerror:             p = none         try:             n = articles[i + 1]         except indexerror:             n = none          return {'prev': p, 'next': n} 

it works, , may inefficient, want use in different model.

i'd make mixin, can't figure out how original model class name can run model.objects.all() , list.

i have far:

class prevnextmixin(object):     objects = list(???.objects.all())     = objects.index(self)     ... 

a mixin still class. code still needs go method. method self argument now.

class prevnextmixin(object):     def get_prev_next(self):         objects = list(self.__class__.objects.all())