def keep_only_fields(self):
        """Keep only fields listed in field_list."""
        for tag in self.record.keys():
            if tag not in self.fields_list:
                record_delete_fields(self.record, tag)
def keep_only_fields(self):
        """Keep only fields listed in field_list."""
        for tag in self.record.keys():
            if tag not in self.fields_list:
                record_delete_fields(self.record, tag)
def keep_only_fields ( self ) : for tag in self . record . keys ( ) : if tag not in self . fields_list : record_delete_fields ( self . record , tag )
Keep only fields listed in field_list.
Keep only fields listed in field_list .