mixin.py

def model_instance_unique_query(obj):
    unique_together_list = list(obj._meta.unique_together)

    if unique_together_list and isinstance(unique_together_list[0], basestring):
        unique_together_list = [unique_together_list]

    unique_together_list += [
        [x.name] for x in ScraperJob._meta.local_fields if x.unique and x.name != 'id'
    ]

    query = Q()

    for unique_together in unique_together_list:
        query |= reduce(operator.and_, [
            Q(**{field: getattr(obj, field)}) for field in unique_together
        ])

    return query


class DjangoUpsertMixin(object):
    def __init__(self, *args, **kwargs):
        super(DjangoUpsertMixin, self).__init__(*args, **kwargs)

    def save(self, *args, **kwargs):
        try:
            obj = self._meta.model.objects.get(model_instance_unique_query(self))
            setattr(self, obj._meta.pk.name, getattr(obj, obj._meta.pk.name))
        except self.DoesNotExist:
            pass
        super(self._meta.model, self).save(*args, **kwargs)

models.py

class TestModel(models.Model, DjangoUpsertMixin):
    name = models.CharField(max_length=255, unique=True)

test.py

import django
django.setup()

from scraper.datasource.drugstore.models import TestModel
TestModel(name='hey').save()