I think you should provide your choices in the form field, not when
creating an instance of the form.
The form would then be something like this:
class StoreLocationHoursForm(BForm):
sl_list= [('-', 'Choose Location'), (u'Super City', u'901
PHILADELPHIA STREET')]
location = forms.ChoiceField(choices=sl_list, required=True)
# rest of fields...
The initial keyword when creating an instance of the form is used to
select which of the choices is rendered as selected.
Haven't tested this though.
- Sævar