Getting name of value from namedtuple

I have a module with collection:

import collections
named_tuple_sex = collections.namedtuple(
                    'FlightsResultsSorter',
                        ['TotalPriceASC',
                         'TransfersASC',
                         'FlightTimeASC',
                         'DepartureTimeASC',
                         'DepartureTimeDESC',
                         'ArrivalTimeASC',
                         'ArrivalTimeDESC',
                         'Airlines']
                    )
FlightsResultsSorter = named_tuple_sex(
    FlightsResultsSorter('TotalPrice', SortOrder.ASC),
    FlightsResultsSorter('Transfers', SortOrder.ASC),
    FlightsResultsSorter('FlightTime', SortOrder.ASC),
    FlightsResultsSorter('DepartureTime', SortOrder.ASC),
    FlightsResultsSorter('DepartureTime', SortOrder.DESC),
    FlightsResultsSorter('ArrivalTime', SortOrder.ASC),
    FlightsResultsSorter('ArrivalTime', SortOrder.DESC),
    FlightsResultsSorter('Airlines', SortOrder.ASC)
)

and in another module, I iterate by this collection and I want to get the name of the item:

for x in FlightsResultsSorter:
            self.sort(x)

so in the code above, I want instead of x (which is an object) to pass, for example, DepartureTimeASC or ArrivalTimeASC.

How can I get this name?