django_aggregate_round.py

from django.db.models import Aggregate


class Round(Aggregate):
    """
    Solution source for future reference: http://stackoverflow.com/a/34622417/4694834
    """
    function = 'ROUND'
    template = '%(function)s(CAST(%(expressions)s AS NUMERIC), {decimals})'
    name = 'Round'

    def __init__(self, data, decimals=2):
        super(Round, self).__init__(data)
        self.template = self.template.format(decimals=decimals)