帮我写一个火车售票系统代码

好的，下面是一个简单的火车售票系统的 Python 代码实现，供您参考：

class Train:
    def __init__(self, train_num, start_station, end_station, departure_time, duration, price):
        self.train_num = train_num
        self.start_station = start_station
        self.end_station = end_station
        self.departure_time = departure_time
        self.duration = duration
        self.price = price

class Ticket:
    def __init__(self, train_num, start_station, end_station, departure_time, duration, price, num):
        self.train_num = train_num
        self.start_station = start_station
        self.end_station = end_station
        self.departure_time = departure_time
        self.duration = duration
        self.price = price
        self.num = num

class TicketOffice:
    def __init__(self, train_list):
        self.train_list = train_list
        self.ticket_list = []

    def search_train(self, start_station, end_station):
        result_list = []
        for train in self.train_list:
            if train.start_station == start_station and train.end_station == end_station:
                result_list.append(train)
        return result_list

    def buy_ticket(self, train_num, num):
        for train in self.train_list:
            if train.train_num == train_num:
                ticket = Ticket(train.train_num, train.start_station, train.end_station, train.departure_time, train.duration, train.price, num)
                self.ticket_list.append(ticket)
                return ticket
        return None

    def show_ticket(self):
        for ticket in self.ticket_list:
            print("Train No.: %s, Start Station: %s, End Station: %s, Departure Time: %s, Duration: %s, Price: %s, Num: %s" % (ticket.train_num, ticket.start_station, ticket.end_station, ticket.departure_time, ticket.duration, ticket.price, ticket.num))

train_list = [Train("G1001", "Beijing", "Shanghai", "08:00", "5h", 500), Train("G1002", "Shanghai", "Beijing", "10:00", "5h", 500), Train("G1003", "Beijing", "Guangzhou", "12:00", "8h", 800)]
office = TicketOffice(train_list)

while True:
    print("1. Search train")
    print("2. Buy ticket")
    print("3. Show ticket")
    print("4. Exit")
    choice = input("Please enter your choice: ")
    if choice == "1":
        start_station = input("Please enter start station: ")
        end_station = input("Please enter end station: ")
        result_list = office.search_train(start_station, end_station)
        for train in result_list:
            print("Train No.: %s, Start Station: %s, End Station: %s, Departure Time: %s, Duration: %s, Price: %s" % (train.train_num, train.start_station, train.end_station, train.departure_time, train.duration, train.price))
    elif choice == "2":
        train_num = input("Please enter train number: ")
        num = input("Please enter number of tickets: ")
        ticket = office.buy_ticket(train_num, num)
        if ticket is not None:
            print("Buy ticket successfully!")
        else:
            print("Sorry, the train is not available.")
    elif choice == "3":
        office.show_ticket()
    elif choice == "4":
        break
    else:
        print("Invalid choice, please try again.")

该系统包含三个类：Train、Ticket 和 TicketOffice。Train 类表示火车，包括火车号、起点站、终点站、出发时间、行车时间和票价等属性。Ticket 类表示车票，包括火车号、起点站、终点站、出发时间、行车时间、票价和购买数量等属性。TicketOffice 类表示售票处，包括火车列表和车票列表等属性，以及搜索火车、购买车票和展示车票等方法。

在程序运行时，用户可以选择进行搜索火车、购买车票和展示车票等操作。具体实现时，可以根据用户的选择调用不同的方法，从而实现相应的功能。