FormSet.forms is an iterable, so just iterate over it

    ...             # Don't bother validating the formset unless each form is valid on its own

    ...             return

    ...         titles = []

    ...         for i in range(0, self.total_form_count()):

    ...             form = self.forms[i]

    ...         for form in self.forms:

    ...             title = form.cleaned_data['title']

    ...             if title in titles:

    ...                 raise forms.ValidationError("Articles in a set must have distinct titles.")