Populate inline formset initial values

admin.py

class ShiftInlineForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        ordinals = [
            'First',
            'Second',
            'Third',
            'Fourth',
            'Fifth',
            'Sixth',
            'Seventh',
            'Eighth',
            'Ninth',
            'Tenth',
        ]

        if not kwargs.get('instance'):
            form_index = kwargs.get('prefix').split('-')[1]

            if form_index.isdigit():
                print(int(form_index))
                self.base_fields["name"].initial = ordinals[int(form_index)]

        super().__init__(*args, **kwargs)


class ShiftInline(admin.TabularInline):
    model = Shift
    extra = 0
    form = ShiftInlineForm