Why doesn't the required=True attribute work on the ChoiceField form field?

Question

Django

Hello!
The problem is this:
When trying to submit form data with an unselected radiobutton, it does not give a message about the impossibility of such an action, such as with an empty Charfield field. It is possible to determine that nothing is selected only when validating the form in the view. How can I fix this or is it a standard widget that does not provide for such work?
The code :

class HorizontalRadioRenderer(forms.RadioSelect.renderer):
    def render(self):
        return mark_safe(u'\n'.join([u'%s\n' % w for w in self]))


class PaySendForm (forms.Form):
    pay_system_choices = (
        ('OSP', ''),
        ('QIW', ''),
        ('P2P', ''),
        ('TST', ''),
    )
    pay_method = forms.ChoiceField(widget=forms.RadioSelect(renderer=HorizontalRadioRenderer),
                                   choices=pay_system_choices, label='', required=True)
    sum = forms.IntegerField(label='', min_value=100, max_value=100000, required=True)

Answer 1

Try to add the widget directly to the html, it will become mandatory Well, or check from_valid