You get that error because 'blank' is model field option. If you want to be able to accept empty values, use required=False instead.
> state = USStateField(initial='CA', required=False) -- You received this message because you are subscribed to the Google Groups "Django users" group. To view this discussion on the web visit https://groups.google.com/d/msg/django-users/-/_ApzlaY9CMQJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
