Валидация формы при переопределённом конструкторе django?

Question

[justdani]

Переопределил конструктор класса формы, и форма не может пройти валидацию. Как сделать правильно?
код ниже:
forms.py

class DepartmentForm(forms.Form):

    def __init__(self, choices, *args):
        super(DepartmentForm, self).__init__(*args)
        self.fields['Department'] = forms.ChoiceField(choices=choices, required=True, label="Департамент")

views.py

if request.method == "POST":
                bc = BCForm(request.POST)
                dep = DepartmentForm(request.POST)
                chk_point = CheckPointForm(request.POST)
                chk_list = CheckListForm(request.POST)
                date_of_chk_list = DateOFCheckListForm(request.POST)
                if bc.is_valid() and chk_point.is_valid() and chk_list.is_valid() and date_of_chk_list.is_valid() and dep.is_valid():
   
            else:
                bc = BCForm()
                dep = DepartmentForm(choices=statement_list)
                chk_point = CheckPointForm()
                chk_list = CheckListForm()
                date_of_chk_list = DateOFCheckListForm()
                return render(request, 'layout/reporters/create_template.html', {'bc': bc,
                                                                                 'dep': dep,
                                                                                 'chkpoint': chk_point,
                                                                                 'chklist': chk_list,
                                                                                 'dateofchklist': date_of_chk_list,
                                                                                 'user': user,
                                                                                 'date': date})