prior_qtr_rev = Window(
    Lag('rev'),
    partition_by=F('company_id'),
    order_by=F('fiscal_end_date').asc()
)

yoy = F('rev') / prior_qtr_rev - 1

companies = Financial.objects.filter(
    company__ticker='AAPL',
).annotate(
    rev_yoy=yoy,
)

yoy = F('rev') / Case(When(prior_qtr_rev=0,
                           then=0),
                      default=prior_qtr_rev,
                      output_field=FloatField()
                      ) - 1

django.core.exceptions.FieldError:
Cannot resolve keyword 'prior_qtr_rev' into field. Choices are: