Formatting horrible if

fields.py

    def run_validators(self, value):
        if value in validators.EMPTY_VALUES:
            return
        errors = []
        for v in self.validators:
            try:
                v(value)
            except ValidationError, e:
                message = None
                if hasattr(e, 'code') and e.code in self.error_messages:
                    error_message = self.error_messages[e.code]
                    default = self.default_error_messages.get(e.code, None)
                    if not default or error_message != default:
                        message = error_message
                        if e.params:
                            message = message % e.params
                if message:
                    errors.append(message)
                else:
                    errors.extend(e.messages)
        if errors:
            raise ValidationError(errors)