Python没有在__init__方法中设置属性

Question

我创建了一个类似于电视及其遥控器的程序。但是当我运行代码并尝试打开电视作为第一选择时，它会显示“AttributeError：无法设置属性”。这是代码：

class Television(object):
    """A TV."""

    def __init__(self, channel=1, volume=10):
        self.channel=channel
        self.volume=volume

    def __str__(self):
        data="\nChannel : "+str(self.channel)+"\nVolume : "+str(self.volume)
        return data

    def __set_channel(self, channel):
        if channel==self.channel:
            print("\nYou are already watching channel ", channel)
        else:
            self.channel=channel
            print("\nYou are now watching channel ", channel)
    channel=property(__set_channel)

    def __set_volume(self, volume):
        self.volume=volume
        print("\nYour current volume is ", volume)
    volume=property(__set_volume)

class Remote(object):
    """A remote control for the TV."""

    def __get_channel(self):
        channel=input("\nEnter the channel number : ", channel)
        if not channel:
            print("\nYou have to enter a channel number.")
        else:
            try:
                int(channel)
            except(ValueError):
                print("\n", channel, " is not a valid channel.")
            else:
                if channel not in range(1, 101):
                    print("\n", channel, " is not in range.")
                else:
                    return channel
    channel=property(__get_channel)

    def __volume_up(self, volume):
        volume+=1
        if volume>100:
            print("\nYou are currently at maximum volume.")
        else:
            return volume

    def __volume_down(self, volume):
        volume-=1
        if volume<0:
            print("\nYou are currently at maximum volume.")
        else:
            return volume

class OFF(object):
    """A TV at off state."""



def get_choice(state):
    """Gets a choice from the user."""

    if state==0:
        print(\
            """
            MUATHASIM TV

            0 - Quit
            1 - Switch the TV on
            """)
    else:
        print(\
            """
            MUATHASIM TV

            0 - Quit
            1 - Switch off the TV
            2 - Change the channel
            3 - Turn up the volume
            4 - Turn down the volume
            """)

    choice=input("\nChoice : ")
    return choice

def main():
    """Main part of the program."""

    remote=Remote()
    choice=None
    state=0
    while choice!="0":
        choice=get_choice(state)

        if state==0:
            if choice=="0":
                print("\nGood Bye!")
            elif choice=="1":
                TV=Television()
            else:
                print("\n", choice, " is not a valid choice.")
        elif state==1:
            if choice=="0":
                print("\nGood Bye!")
            elif choice=="1":
                TV=OFF()
            elif choice=="2":
                channel=remote.channel
                TV.channel=channel
            elif choice=="3":
                volume=remote.__volume_up(TV.volume)
                TV.volume=volume
            elif choice=="4":
                volume=remote.__volume_down(TV.volume)
                TV.volume=volume
            else:
                print("\n", choice, "is not a valid choice.")




main()

input("\n\n\nPress the Enter key to exit.")

Answer 1

问题在于您创建属性的方式： channel=property(__set_channel)使用 getter函数 __set_channel创建一个属性。 您必须创建适当的getter函数，例如：

def __get_channel(self):
    return self._channel

并将该属性创建为

channel = property(__get_channel, __set_channel)

最后，您需要修复您的setter函数：self.channel = channel将调用setter函数，从而导致无限循环。请改用self._channel = channel。