如何在Django查询中执行循环

Question

我使用this link和this link编写了以下代码，以查询在我的一个分支机构半径内的企业。

from django.db.models import Func, F
from li_app.models import Branch, Business

class Sin(Func):
    function = 'SIN'

class Cos(Func):
    function = 'COS'

class Acos(Func):
    function = 'ACOS'

class Radians(Func):
    function = 'RADIANS'

class Degrees(Func):
    function = 'DEGREES'

def filter_within_distance(
    branch_kwargs, 
    business_kwargs, 
    radius
):

    KM_PER_DEGREE = 111.045
    branch = Branch.objects.filter(**branch_kwargs)[0]

    lat_point = branch.branch_latitude
    long_point = branch.branch_longitude
    radlat = Radians(lat_point)
    radlong = Radians(long_point)
    radflat = Radians(F('business_latitude'))
    radflong = Radians(F('business_longitude'))
    Expression = KM_PER_DEGREE * Degrees(Acos(Cos(radlat) * Cos(radflat) * 
            Cos(radflong - radlong) + Sin(radlat) * Sin(radflat)))

    latitude_delta = radius / KM_PER_DEGREE
    longitude_delta = radius / (KM_PER_DEGREE * Cos(radlat))
    lat_range = (float(lat_point) - latitude_delta, float(lat_point) + latitude_delta)
    long_range = (float(long_point) - longitude_delta, float(long_point) + longitude_delta)
    business_kwargs['business_latitude__range'] = lat_range
    business_kwargs['business_longitude__range'] = long_range

    return Business.objects.filter(**business_kwargs).annotate(distance=Expression).filter(distance__lte=radius).order_by('distance')

现在，我想修改上面的查询，以使所有公司都在我所有分支机构的半径范围内。我想避免python循环，因此，如果有任何方法可以在查询中执行循环，那将非常棒。