Django multiple forms with modelchoicefield -> too many queries

Question

I have a table of forms of the same class which contains ModelChoiceField. And each form in one row has the same queryset for this field. Problem is that every time the form is rendered, it is a new query which increases unbearably the number of queries.

The only solution I came up with is to construct the form on the go with js instead of letting django to render it itself. Is there a way to cache these querysets or somewhat preload it at once?

views.py:
shift_table=[]
for project in calendar_projects:
    shift_table.append([])
    project_branches = project.branches.all()
    for i, week in enumerate(month):
        for day in week:
            shift_table[-1].append(
                CreateShiftCalendarForm(initial={'date': day}, branch_choices=project_branches))


forms.py:
CreateShiftCalendarForm(EditShiftCalendarForm):

    class Meta(ShiftForm.Meta):
        fields = ('project_branch', 'date') + ShiftForm.Meta.fields
        widgets = {'date': forms.HiddenInput(), 'length': forms.NumberInput(attrs={'step': 'any'}), 'project_branch': forms.Select()}

    def __init__(self, *args, **kwargs):
        branch_choices = kwargs.pop('branch_choices', ProjectBranch.objects.none())
        super(CreateShiftCalendarForm, self).__init__(*args, **kwargs)

        self.fields['project_branch'].queryset = branch_choices
        self.fields['project_branch'].empty_label = None

Answer 1

I subclassed ChoiceField as suggested by GwynBleidD and it works sufficiently for now.

class ListModelChoiceField(forms.ChoiceField):
    """
    special field using list instead of queryset as choices
    """
    def __init__(self, model, *args, **kwargs):
        self.model = model
        super(ListModelChoiceField, self).__init__(*args, **kwargs)

    def to_python(self, value):

        if value in self.empty_values:
            return None
        try:
            value = self.model.objects.get(id=value)
        except self.model.DoesNotExist:
            raise ValidationError(self.error_messages['invalid_choice'], code='invalid_choice')
        return value


    def valid_value(self, value):
        "Check to see if the provided value is a valid choice"

        if any(value.id == int(choice[0]) for choice in self.choices):
            return True
        return False