sample.py

from django.core.cache import cache


def get_my_choices():
    key = 'my-dynamic-choices-key'
    res = cache.get(key)
    if not res:
        # we are casting to list here so we store a list in the cache, not a QuerySet instance)
        res = list(User.objects.values_list('id', 'email'))  # this is just an example replace it with your model/fields
        cache.set(key, res, 60*60*24)  # cache for a day
    return res