int значення в radio форму

class ReviewForm(ModelForm):
    RATING_CHOICES = ((1, '1'), (2, '2'), (3, '3'), (4, '4'), (5, '5'),)
    rate = forms.TypedChoiceField(choices=RATING_CHOICES, \
                                  widget=forms.RadioSelect, coerce=int)

    def clean_rate(self):
        if self.cleaned_data['rate'] >= 1 and self.cleaned_data['rate'] <= 5:
            return self.cleaned_data['rate']
        else:
            raise forms.ValidationError(_("Rating error"))

    class Meta:
        model = Reviews
        fields = ('rate', 'message', 'content_type', 'object_id')
        widgets = {
            'content_type' : forms.HiddenInput(),
            'object_id' : forms.HiddenInput()
        }