请写一个飞机订票系统的代码

以下是一个简单的飞机订票系统的代码示例：

class Flight:
    def __init__(self, flight_number, origin, destination, departure_time, arrival_time):
        self.flight_number = flight_number
        self.origin = origin
        self.destination = destination
        self.departure_time = departure_time
        self.arrival_time = arrival_time
        self.seats = {}

    def add_seat(self, seat_number, passenger):
        if seat_number not in self.seats:
            self.seats[seat_number] = passenger
            print(f"座位号 {seat_number} 已成功预订给 {passenger}")
        else:
            print(f"座位号 {seat_number} 已被预订")

    def remove_seat(self, seat_number):
        if seat_number in self.seats:
            del self.seats[seat_number]
            print(f"座位号 {seat_number} 的预订已取消")
        else:
            print(f"座位号 {seat_number} 未被预订")


class BookingSystem:
    def __init__(self):
        self.flights = {}

    def add_flight(self, flight):
        self.flights[flight.flight_number] = flight
        print(f"航班 {flight.flight_number} 已成功添加")

    def remove_flight(self, flight_number):
        if flight_number in self.flights:
            del self.flights[flight_number]
            print(f"航班 {flight_number} 已成功删除")
        else:
            print(f"航班 {flight_number} 不存在")

    def book_seat(self, flight_number, seat_number, passenger):
        if flight_number in self.flights:
            flight = self.flights[flight_number]
            flight.add_seat(seat_number, passenger)
        else:
            print(f"航班 {flight_number} 不存在")

    def cancel_booking(self, flight_number, seat_number):
        if flight_number in self.flights:
            flight = self.flights[flight_number]
            flight.remove_seat(seat_number)
        else:
            print(f"航班 {flight_number} 不存在")


# 示例用法
booking_system = BookingSystem()

# 添加航班
flight1 = Flight("AA123", "Beijing", "Shanghai", "10:00", "12:00")
booking_system.add_flight(flight1)

# 预订座位
booking_system.book_seat("AA123", "A1", "John")
booking_system.book_seat("AA123", "A2", "Alice")

# 取消预订
booking_system.cancel_booking("AA123", "A2")

# 删除航班
booking_system.remove_flight("AA123")

上述代码中，Flight类表示航班，具有航班号、起始地、目的地、起飞时间、到达时间和座位信息等属性。可以使用add_seat方法预订座位，使用remove_seat方法取消座位预订。

BookingSystem类表示订票系统，具有航班列表。可以使用add_flight方法添加航班，使用remove_flight方法删除航班，使用book_seat方法预订座位，使用cancel_booking方法取消座位预订。

示例用法展示了如何使用订票系统进行航班和座位的管理