airtravel.py

""" Model for aircraft flights"""

class Flight:
    """A flight with a particular passenger aircraft."""
    def __init__(self,number, aircraft):
        if not number[:2].isalpha():
            raise ValueError("No airline code in '{}'".format(number))

        if not number[:2].isupper():
            raise ValueError("Invalid airline code in '{}'".format(number))

        if not number[2:].isdigit and int(number[2:]) <= 9999:
            raise ValueError("Invalid route number '{}'".format(number))

        self._number = number
        self._aircraft = aircraft

        rows, seats = self._aircraft.seating_plan()
        self._seating = [None] + [ {letter: None for letter in seats} for _ in rows]

    def number(self):
        return self._number

    def airline(self):
        return self._number[:2]

    def aircraft_model(self):
        return self._aircraft.model()

    def _parse_seat(self,seat):
        """ Parse a seat designator into a valid row and letter.

        Args:
            seat: A seat designator such as 12F

        Returns:
            A tuple containing an integer and a string for row and seat.
        """
        row_numbers, seat_letters = self._aircraft.seating_plan()

        letter = seat[-1]
        if letter not in seat_letters:
            raise ValueError("Invalid seat letter {}".format(letter))

        row_text = seat[:-1]
        try:
            row = int(row_text)
        except ValueError:
            raise ValueError("Invalid seat row {}".format(row_text))

        if row not in row_numbers:
            raise ValueError("Invalid row number {}".format(row))

        return row, letter

    def allocate_seat(self,seat,passenger):
        """Allocate a seat to a passenger.

        Args:
            seat : A seat designator such as '12C' or '21F'
            passenger: The passenger name.

        Raises:
            ValueError: If the seat is unavailable
        """
        row, letter = self._parse_seat(seat)

        if self._seating[row][letter] is not None:
            raise ValueError("Seat {} already occupied".format(seat))

        self._seating[row][letter] = passenger

    def relocate_passenger(self, from_seat, to_seat):
        """
        Allocate a seat to a passenger.

        Args:
            from_seat : The existing seat designator for the
                        passenger to be moved
            to_seat : The new seat designator.
        """
        from_row,from_letter = self._parse_seat(from_seat)
        if self._seating[from_row][from_letter] is None:
            raise ValueError("No passenger to relocate in seat {}".format(from_seat))

        to_row, to_letter = self._parse_seat(to_seat)
        if self._seating[to_row][to_letter] is not None:
            raise ValueError("Seat {} already occupied".format(to_seat))

        self._seating[to_row][to_letter] = self._seating[from_row][from_letter]
        self._seating[from_row][from_letter] = None

    def num_available_seats(self):
        return sum(sum(1 for s in row.values() if s is None)
                   for row in self._seating
                   if row is not None)

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

    def _passenger_seats(self):
        """An iterable series of passenger seating allocations."""
        row_numbers, seat_letters = self._aircraft.seating_plan()
        for row in row_numbers:
            for letter in seat_letters:
                passenger = self._seating[row][letter]
                if passenger is not None:
                    yield(passenger, "{}{}".format(row, letter))

class Aircraft:
    def __init__(self, registration, model, num_rows, num_seats_per_row):
        self._registration = registration
        self._model = model
        self._num_rows = num_rows
        self._num_seats_per_row = num_seats_per_row

    def registration(self):
        return self._registration

    def model(self):
        return self._model

    def seating_plan(self):
        return (range(1,self._num_rows + 1),
                "ABCDEFGHJK"[:self._num_seats_per_row])


def make_flight():
    f = Flight("BA758",Aircraft("G-EUPT","Airbus A319", num_rows=22, num_seats_per_row=6))
    f.allocate_seat("12A", 'Guido van Rossum')
    f.allocate_seat("15F", 'Bjarne Stroustrup')
    f.allocate_seat("15E", 'Anders Hejlsberg')
    f.allocate_seat("1C", 'John McCarthy')
    f.allocate_seat("1D", 'Richard Hickey')
    return f

def console_card_printer(passenger, seat, flight_number, aircraft):
    output = "| Name: {0}" \
             "  Flight: {1}" \
             "  Seat: {2}"   \
             "  Aircraft: {3}" \
             " |".format(passenger,flight_number, seat, aircraft)
    banner = '+' + '-' * (len(output)-2) + '+'
    border = '|' + ' ' * (len(output)-2) + '|'
    lines = [banner, border,output, border,banner]
    card = '\n'.join(lines)
    print(card)
    print()