Django-通过request.user.somechoice\u集.all()

class SpamForm(ModelForm):
    some_choices = fields.MultipleChoiceField()

    def __init__(self, *args, **kwargs):
        super(SpamForm, self).__init__(*args, **kwargs)
        self.fields['some_choices'].choices = [[choice.pk, choice.description] for choice in self.instance.user.somechoice_set.all()]

    class Meta:
        model = Spam

request.user (在传递到表单中的实例上设置)。有更好的办法吗?