The Python Apprentice

Making Flight create boarding cards

To the Flight class we add a new method make_boarding_cards() which accepts a card_printer:

class Flight:    # ...    def make_boarding_cards(self, card_printer):        for passenger, seat in sorted(self._passenger_seats()):            card_printer(passenger, seat, self.number(),             self.aircraft_model())

This tells the card_printer to print each passenger, having sorted a list of passenger-seat tuples obtained from a _passenger_seats() implementation detail method (note the leading underscore). This method is in fact a generator function which searches all seats for occupants, yielding the passenger and the seat number as they are found:

def _passenger_seats(self):    """An iterable series of passenger seating allocations.""" row_numbers, ...