Django ORM how to Round an Avg result

I have a model in which I use Django ORM to extract Avg of values from the table. I want to Round that Avg value, how do I do this?

See below I am extracting Avg price from Prices model grouped by date in format YYYY-MM, I want to automatically extract the average values rounded to the closest number.

rs = Prices.objects.all.extra(select={
    'for_date': 'CONCAT(CONCAT(extract( YEAR from for_date ), "-"),
        LPAD(extract(MONTH from for_date), 2, "00"))'
    }).values('for_date').annotate(price=Avg('price')).order_by('-for_date')