用python写一个航班预订系统包括新建订单、打开订单、更新订单、删除订单功能。 其中新建订单要求如下 （1）航班日期 输入框存在默认的日期格式：__/__/__ 表示mm/dd/yy,必须填系统当前时间以后的时间，如果不符合，系统弹出提示框“此日期后的航班日期有效+系统时间”。 （2）起点和终点不能为同一城市。。 （3）选中一个航班后，会自动填入，航班号、起飞时间、到达时间、航空公司、价格、总计的订单信息。机票数默认为1，舱位种类默认为经济舱，如果更改机票数，总计会自动更新，更新仓位种类，价格也会更新。 （4）不输入名称，插入订单按钮为不可用。 （5）信息填完整后，点击插入订单。系统会自动生成唯一订单号

好的，我可以为您提供一些参考代码，但是需要注意的是，由于航班信息和订单信息需要从数据库中读取和写入，所以代码可能比较复杂。以下是一个简单的示例：

import datetime
import random

class Flight:
    def __init__(self, flight_number, departure_city, arrival_city, departure_time, arrival_time, airline, price):
        self.flight_number = flight_number
        self.departure_city = departure_city
        self.arrival_city = arrival_city
        self.departure_time = departure_time
        self.arrival_time = arrival_time
        self.airline = airline
        self.price = price

class Order:
    def __init__(self, order_id, flight, passenger_name, ticket_num=1, cabin_type='Economy'):
        self.order_id = order_id
        self.flight = flight
        self.passenger_name = passenger_name
        self.ticket_num = ticket_num
        self.cabin_type = cabin_type
        self.total_price = self.ticket_num * self.flight.price

class BookingSystem:
    def __init__(self):
        self.flights = []
        self.orders = []
        self.current_order = None

    def add_flight(self, flight):
        self.flights.append(flight)

    def search_flight(self, departure_city, arrival_city, date):
        available_flights = []
        for flight in self.flights:
            if flight.departure_city == departure_city and flight.arrival_city == arrival_city and flight.departure_time.date() == date.date():
                available_flights.append(flight)
        return available_flights

    def create_order(self, flight, passenger_name):
        order_id = str(datetime.datetime.now().timestamp()) + str(random.randint(100, 999))
        order = Order(order_id, flight, passenger_name)
        self.orders.append(order)
        self.current_order = order
        return order

    def update_order(self, ticket_num, cabin_type):
        self.current_order.ticket_num = ticket_num
        self.current_order.cabin_type = cabin_type
        self.current_order.total_price = self.current_order.ticket_num * self.current_order.flight.price
        return self.current_order

    def delete_order(self, order):
        self.orders.remove(order)

    def generate_order_id(self):
        order_id = str(datetime.datetime.now().timestamp()) + str(random.randint(100, 999))
        return order_id

# Example usage:
booking_system = BookingSystem()

# Add flights
flight1 = Flight('CA123', 'Shanghai', 'Beijing', datetime.datetime(2022, 1, 1, 8, 0), datetime.datetime(2022, 1, 1, 10, 30), 'Air China', 800)
flight2 = Flight('MU456', 'Shanghai', 'Guangzhou', datetime.datetime(2022, 1, 1, 12, 0), datetime.datetime(2022, 1, 1, 14, 0), 'China Eastern', 600)
booking_system.add_flight(flight1)
booking_system.add_flight(flight2)

# Search for available flights
available_flights = booking_system.search_flight('Shanghai', 'Beijing', datetime.datetime(2022, 1, 1, 0, 0))
for flight in available_flights:
    print(flight.flight_number, flight.departure_time, flight.price)

# Create an order
order = booking_system.create_order(flight1, 'John Smith')
print(order.order_id, order.passenger_name, order.flight.flight_number, order.total_price)

# Update the order
updated_order = booking_system.update_order(2, 'Business')
print(updated_order.ticket_num, updated_order.cabin_type, updated_order.total_price)

# Delete the order
booking_system.delete_order(order)

# Generate a unique order ID
order_id = booking_system.generate_order_id()
print(order_id)

此代码只是一个简单的示例，实际的系统可能需要更多的功能和错误处理。此外，需要将航班和订单信息存储在数据库中，以便可以随时检索和更新它们。