Django query an unknown number of multiple date ranges

Question

I have a form which allows a user to select users by multiple age ranges: 18-24, 25-34, 35-44 etc. Currently if a user selects the first two fields in the multiple selection

Answer 1

As you say in your question, you can use Q() objects and combine them together. It's not a problem that you don't know how many Q() objects there will be. Generate a list of the Q() objects, then reduce the list to a single Q().

from operator import or_

# import for Python 3, not required in Python 2
from functools import reduce

ranges = [(18,24), (35, 44)]  # hardcoded as an example, you can dynamically generate this
qs = [Q(dob_range=[dob_from_, dob_to]) for (dob_from_, dob_to) in ranges]
# combine the qs
dob_q = reduce(or_, qs, Q())

query = User.objects.filter(
    dob_q,
    gender__in=genders,
    created__in=dates,
    data_source__in=sources,
)

If you are unfamiliar with reduce and or_, you can get the same result by looping through the list:

qs = [Q(dob_range=[dob_from_, dob_to]) for (dob_from_, dob_to) in ranges]
dob_q = Q()
for q in qs:
    dob_q = dob_q | q