def _merge_fields_and_pk(pk, fields):
    fields_and_pk = OrderedDict()
    fields_and_pk['pk'] = pk
    fields_and_pk[pk.name] = pk
    fields_and_pk.update(fields)

    return fields_and_pk
    def get_field_info(self, field):
        """
        Given an instance of a serializer field, return a dictionary
        of metadata about it.
        """
        field_info = OrderedDict()
        field_info['type'] = self.label_lookup[field]
        field_info['required'] = getattr(field, 'required', False)

        attrs = [
            'read_only', 'label', 'help_text',
            'min_length', 'max_length',
            'min_value', 'max_value'
        ]

        for attr in attrs:
            value = getattr(field, attr, None)
            if value is not None and value != '':
                field_info[attr] = force_text(value, strings_only=True)

        if not field_info.get('read_only') and hasattr(field, 'choices'):
            field_info['choices'] = [
                {
                    'value': choice_value,
                    'display_name': force_text(choice_name, strings_only=True)
                }
                for choice_value, choice_name in field.choices.items()
            ]

        return field_info