用Python写一个简单的，查询车票信息，包括时间，张数，车次等信息，购票时输入车次，张数，显示购买成功，更新车票张数信息，改签退票也要显示修改后的车票信息等的一个程序

以下是一个简单的示例程序，用于查询、购买、改签和退票车票信息。请注意，这只是一个基础的示例，实际应用中可能需要更复杂的逻辑和数据存储方式。

class Ticket:
    def __init__(self, train_number, date, available_tickets):
        self.train_number = train_number
        self.date = date
        self.available_tickets = available_tickets

class TicketSystem:
    def __init__(self):
        self.tickets = []

    def add_ticket(self, train_number, date, available_tickets):
        ticket = Ticket(train_number, date, available_tickets)
        self.tickets.append(ticket)

    def find_ticket(self, train_number, date):
        for ticket in self.tickets:
            if ticket.train_number == train_number and ticket.date == date:
                return ticket
        return None

    def book_ticket(self, train_number, date, num_tickets):
        ticket = self.find_ticket(train_number, date)
        if ticket is None:
            print("该车次不存在或日期错误")
            return

        if num_tickets > ticket.available_tickets:
            print("余票不足")
            return

        ticket.available_tickets -= num_tickets
        print("购买成功")

    def modify_ticket(self, train_number, date, num_tickets):
        ticket = self.find_ticket(train_number, date)
        if ticket is None:
            print("该车次不存在或日期错误")
            return

        ticket.available_tickets += num_tickets
        print("修改成功")

    def refund_ticket(self, train_number, date, num_tickets):
        ticket = self.find_ticket(train_number, date)
        if ticket is None:
            print("该车次不存在或日期错误")
            return

        ticket.available_tickets += num_tickets
        print("退票成功")

# 示例用法
ticket_system = TicketSystem()
ticket_system.add_ticket("G1234", "2022-01-01", 100)
ticket_system.book_ticket("G1234", "2022-01-01", 2)
ticket_system.modify_ticket("G1234", "2022-01-01", 1)
ticket_system.refund_ticket("G1234", "2022-01-01", 1)

这个程序使用了两个类：`Ticket` 表示车票信息，包括车次、日期和可用张数；`TicketSystem` 是一个车票管理系统，负责添加、查询、购买、改签和退票等操作。

你可以根据实际需求，进一步完善和扩展这个程序。例如，可以引入用户系统、持久化数据存储等功能。