我有一个Django的clean方法的问题，因为表单的clean方法不会加载模板中的错误。有人能帮助我吗？
template.html

{% extends "index.html" %}
{% block header %}
    <div id="container-register">
        <div class="logo-register">Zarejestruj się</div>
            <div class="register-form">
                <form method="post">
                    {% csrf_token %}
                {% for field in form %}
                   {{ field }} {{ field.errors }} <br>
                {% endfor %}
                <input type="submit" value="Zarejestruj">
                </form>
            </div>
    </div>
{% endblock  %}

view.py

class AddUserView(View):
    template_name = 'add_user.html'
    def get(self,request):
        return render(request, self.template_name,{
            'form': AddUserForm()
        })
    def post(self,request):
        form = AddUserForm(request.POST)
        if form.is_valid():
            User.objects.create_user(
                username=form.cleaned_data.get('username'),
                email=form.cleaned_data.get('email'),
                password=form.cleaned_data.get('password'),
                first_name=form.cleaned_data.get('first_name'),
                last_name=form.cleaned_data.get('last_name')
            )
            return redirect('/login')
        else:
            return render(request, self.template_name, context={
                'form': AddUserForm()
            })

forms.py

class AddUserForm(forms.Form):
    username = forms.CharField(widget=forms.TextInput(attrs={'placeholder': 'Nazwa użytkownika'}), max_length=100)
    password = forms.CharField(widget=forms.PasswordInput(attrs={'placeholder': 'Hasło'}), max_length=100)
    password_repeat = forms.CharField(widget=forms.PasswordInput(attrs={'placeholder': 'Powtórz hasło'}),
                                      max_length=100)
    first_name = forms.CharField(widget=forms.TextInput(attrs={'placeholder': 'Imię'}), max_length=100)
    last_name = forms.CharField(widget=forms.TextInput(attrs={'placeholder': 'Nazwisko'}), max_length=100)
    email = forms.EmailField(widget=forms.TextInput(attrs={'placeholder': 'Email'}), max_length=100)

    def clean_username(self):
        if User.objects.filter(username=self.cleaned_data.get('username')).exists():
            raise ValidationError('Ten login jest już zajęty')
        return self.cleaned_data.get('username')

    def clean_password_repeat(self):
        if self.cleaned_data.get('password') != self.cleaned_data.get('password_repeat'):
            raise ValidationError('Podane hasła różnią się od siebie!')
        return self.cleaned_data.get('password_repeat')

我检查了页面源代码，看看errors类是否添加到了html文件中。