Estoy tratando de implementar un formset de edición. Luego, estoy creando una instancia de los objetos en el formset usando modelformset_factory. Cuando la solicitud no es POST, el formset se carga perfectamente, pero, si la solicitud es POST, el constructor formset genera un MultiValueDictKeyError.

Este es mi código.

forms.py

class SchoolSectionForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        self.helper = FormHelper()
        self.helper.form_tag = False

        self.helper.layout = Layout(
            Div(
                'name',
                css_class='name',
            ),
        )

        super(SchoolSectionForm, self).__init__(*args, **kwargs)

    class Meta:
        model = SchoolSection

        exclude = [
            'school',
            'created_by',
        ]


class SectionBreakFormSet(BaseFormSet):

    def __init__(self, *args, **kwargs):
        super(SectionBreakFormSet, self).__init__(*args, **kwargs)


class SectionBreakForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        self.helper = FormHelper()
        self.helper.form_tag = False

        self.helper.layout = Layout(
            Div(
                Div(
                    'start_time',
                    css_class='start_time',
                ),
                Div(
                    'end_time',
                    css_class='end_time',
                ),
            css_class='formset_element',
            )
        )

        super(SectionBreakForm, self).__init__(*args, **kwargs)

    class Meta:
        model = SectionBreak

        exclude = [
            'school_section',
            'created_by',
        ]

vistas.py

def school_section_edit(request, section_id):

    section = get_object_or_404(
        SchoolSection,
        id=section_id,
    )

    current_school = request.user.current_school
    school_sections_list = current_school.schoolsection_set.all()

    section_break_formset = modelformset_factory(
        SectionBreak,
        max_num=3,
        extra=0,
        form=SectionBreakForm,
    )

    formset_qset = SectionBreak.objects.filter(school_section=section)

    formset = section_break_formset(queryset=formset_qset)
    school_section_form = SchoolSectionForm(instance=section)

    if request.method == 'POST':
        school_section_form = SchoolSectionForm(request.POST)

        # Bug raises in this line
        formset = section_break_formset(request.POST, queryset=formset_qset) 
        # Bug raises in this line


        if school_section_form.is_valid() and formset.is_valid():

            school_section_form.save()
            formset.save()

            messages.success(
                request,
                u'xxx',
            )

            return HttpResponseRedirect(reverse('school:school_section_add'))

        else:
            messages.error(
                request,
                u'xxx',
            )

    return render(request, 'school/schoolsection_add.html', {
        'school_section_form': school_section_form,
        'formset': formset,
        'school_sections_list': school_sections_list,
    })

modelo

<form class="new_section_form" method="post" action="">
    <div class="school_section_form">
        {% crispy school_section_form %}
    </div>

    <h3>Horarios de descanso:</h3>

    <div class="section_break_formset">
        {% crispy formset formset.form.helper %}
    </div>

    <button class="button color">guardar</button>
</form>

Cuando publico el formulario ... crashh .... tengo este error

gracias por la ayuda...

Tipo de excepción: MultiValueDictKeyError en / administrador / ciclo-educativo / editar / 34 / Valor de excepción: "La clave u'form-0-id 'no se encuentra en <> QueryDict: {u'name': [u'Primaria '], u 'form-MAX_NUM_FORMS': [u'3 '], u'form-TOTAL_FORMS': [u'1 '], u'form-0-start_time': [u'07: 00: 00 '], u'form -0-final-hora-en--l--l-P-6-j-C-1-j-C-1-j-C-1-j-C-1-j-C-1-j-C-1-j-C-1-j-C-1-j-C-1 "