How to remove from modelformset?

Question

Django

Good day.
Either I'm completely stupid or I don't know anymore.
The second day I suffer, I can not delete from the modelformset with the button on the site.
Actually a piece of the template

{{ formset.management_form }}
    {% for form in formset %}
        {{ form.id }}
        {{ form.DELETE }}
       <tr class="edt {% if forloop.first  %} shadow {% endif %}"
               {% if forloop.counter|divisibleby:"2" %}style="background-color: white"
               {% else %} style="background-color: #F2F2F2"
               {% endif %}>
           <td>  {{ form.title }} </td>
           <td>{{ form.priceMazut }} </td>
           <td>{{ form.priceSPBT }} </td>
           <td>{{ form.priceDTl }} </td>
           <td>{{ form.priceDTm }} </td>
           <td>{{ form.priceDTz }} </td>
          
           <td class="last"></td>
       </tr>

    {% endfor %}

here is the view

def manage_articles(request):
    if not request.user.is_staff:
            return redirect('/')
    ArticleFormSet = modelformset_factory(Article, fields=('title', 'priceMazut', 'priceSPBT', 
                                                              'priceDTl', 'priceDTm', 'priceDTz'))
    if request.method == 'POST':
        formset = ArticleFormSet(request.POST, request.FILES)
        if formset.is_valid():
            formset.save()
            return redirect('/?$')
    else:
        formset = ArticleFormSet()
    return render(request, "table/manage_articles.html", {"formset": formset})

forms.py

class ArticleForm(forms.ModelForm):

    class Meta:
        model = Article
        fields = ('title', 'priceMazut', 'priceSPBT', 'priceDTl', 'priceDTm', 'priceDTz')


ArticleFormSet = modelformset_factory(Article, form=ArticleForm, can_delete=True)
formset = ArticleFormSet()


class ArticleFormSet(BaseModelFormSet):
    def clean(self):
        super(ArticleFormSet, self).clean()

        for form in self.forms:
            title = form.cleaned_data['title'].upper()
            form.cleaned_data['title'] = title
            form.instance.title = title
            priceMazut = form.cleaned_data['priceMazut'].upper()
            form.cleaned_data['priceMazut'] = priceMazut
            form.instance.priceMazut = priceMazut
            priceSPBT = form.cleaned_data['priceSPBT'].upper()
            form.cleaned_data['priceSPBT'] = priceSPBT
            form.instance.priceSPBT = priceSPBT
            priceDTl = form.cleaned_data['priceDTl'].upper()
            form.cleaned_data['priceDTl'] = priceDTl
            form.instance.priceDTl = priceDTl
            priceDTm = form.cleaned_data['priceDTm'].upper()
            form.cleaned_data['priceDTm'] = priceDTm
            form.instance.priceDTm = priceDTm
            priceDTz = form.cleaned_data['priceDTz'].upper()
            form.cleaned_data['priceDTz'] = priceDTz
            form.instance.priceDTz = priceDTz

Deleted all my futile attempts to prescribe the deletion, my head is boiling
Re-read the documentation several times
Apparently still quite stupid

Answer 1

I figured out the deletion, but now when I add new rows or edit existing ones, it gives an error instead of saving
AttributeError at /table/edit/
'NoneType' object has no attribute 'group'

def manage_articles(request):
    if not request.user.is_staff:
            return redirect('/')
    ArticleFormSet = modelformset_factory(Article, fields=('title', 'priceMazut', 'priceSPBT',
                                                           'priceDTl', 'priceDTm', 'priceDTz'))
    if request.method == 'POST':
        enurl = urllib.parse.urlencode(request.POST)  
        matchobj = re.search(r'del_btn\d', enurl) 
        pri_key = matchobj.group()[-1]
        if matchobj:
               query = Article.objects.get(pk=pri_key).delete()
               formset = ArticleFormSet(request.POST, request.FILES)
               if formset.is_valid():
                   formset.save()
                   formset = ArticleFormSet(queryset=Article.objects.all())
                   return redirect('/?$')
        else:
            formset = ArticleFormSet(request.POST, request.FILES)
            if formset.is_valid():
                formset.save()

                return redirect('/?$')
    else:
        formset = ArticleFormSet()
    return render(request, "table/manage_articles.html", {"formset": formset})

{{ formset.management_form }}
    {% for form in formset %}
        {{ form.id }}
        {{ form.instance.id }}
        {{ form.DELETE }}
       <tr class="edt {% if forloop.first  %} shadow {% endif %}"
               {% if forloop.counter|divisibleby:"2" %}style="background-color: white"
               {% else %} style="background-color: #F2F2F2"
               {% endif %}>

           <td>  {{ form.title }} </td>
           <td>{{ form.priceMazut }} </td>
           <td>{{ form.priceSPBT }} </td>
           <td>{{ form.priceDTl }} </td>
           <td>{{ form.priceDTm }} </td>
           <td>{{ form.priceDTz }} </td>
           <td><input type="submit" name="del_btn{{ form.instance.id }}" value="Delete"/></td>
           <td class="last"></td>
       </tr>