def clean_name(self):
        "Ensures a contact with the same name doesn't already exists"
        instance = getattr(self, 'instance', None)
        name = self.cleaned_data['name']
        if instance and not instance.id:
            slug = unicode(name).replace(" ", "-")
            slug = defaultfilters.slugify(unidecode(slug))
            if ContactType.objects.filter(slug=slug).exists():
                raise forms.ValidationError(
                    _("Contact Type with such name already exists."))
        return name
dataset/ETHPy150Open treeio/treeio/treeio/identities/forms.py/ContactTypeForm.clean_name/original