Andrey K

CELERYBEAT_SCHEDULER = 'djcelery.schedulers.DatabaseScheduler'

import itertools
objects = itertools.chain(TVlist.objects.all(), IntList.objects.all())

class CourseForm(forms.ModelForm):
    currency_from = forms.ModelChoiceField(queryset=Currency.objects.filter(is_active=True))

class Rates(models.Model):
    class Meta:
        # делает уникальным направление обмена
        unique_together = ("_from", "_to")

    # эталон
    _from = models.ForeignKey(Currencies, verbose_name='Эталон', related_name="rates_from")

    # валюта
    _to = models.ForeignKey(Currencies, verbose_name='Валюта', related_name="rates_to")

    rate = models.FloatField(verbose_name='Курс')