models_q

from django.db.models import Count
from django.db.models import Q


for item in a_list :
    data = qs.aggregate(
        p1=Count('pk', filter=Q(**{item: True})),
        p2=Count('pk', filter=Q(**{item: False})),
        p3=Count('pk', filter=Q(**{item: None})),
    )
    param1[item] = data['p1'] or 0
    param2[item] = data['p2'] or 0
    param3[item] = data['p3'] or 0