写一段电梯的程序代码

这是一个简单的电梯程序代码示例：

class Elevator:
    def __init__(self, floor=1):
        self.floor = floor
        self.direction = "up"
        self.is_running = False

    def go_up(self):
        if self.floor < 5:
            self.floor += 1
            print("Now we are at floor", self.floor)

    def go_down(self):
        if self.floor > 1:
            self.floor -= 1
            print("Now we are at floor", self.floor)

    def start(self):
        self.is_running = True
        print("Elevator is starting.")

    def stop(self):
        self.is_running = False
        print("Elevator is stopping.")


elevator = Elevator()
elevator.start()

while elevator.is_running:
    if elevator.direction == "up":
        if elevator.floor == 5:
            elevator.direction = "down"
        else:
            elevator.go_up()
    else:
        if elevator.floor == 1:
            elevator.direction = "up"
        else:
            elevator.go_down()

elevator.stop()

这个程序创建了一个 Elevator 类表示电梯，包含了电梯所在的楼层、电梯方向、电梯运行状态等属性，以及上升、下降、启动、停止等方法。在主程序中，电梯会不断地上升和下降，直到电梯停止运行。