描述符' __ init __'超级'对象需要参数

时间:2014-05-27 01:52:49

标签: python descriptor python-decorators

我正在尝试用Python制作面向对象的基于文本的游戏,并尝试实现我的第一个属性和装饰器。使用书'Python 3 Object Oriented Programming'中的第5章,我试图使用所讨论的示例和概念来获取以下代码,以便在实例化时设置Game-object的'current_room'属性:

class Room(object):
    ''' An area of the game's map.'''
    def __init__(self):
        print("Accessing the Room __init__ method.")


class FirstRoom(Room):
    ''' Just some room.'''
    def __init__(self):
        print("Accessing the FirstRoom __init__ method.")
        super.__init__()


class SecondRoom(Room):
    ''' Just some other room.'''
    def __init__(self):
        print("Accessing the SecondRoom __init__ method.")
        super.__init__()


class Game(object):
    ''' Creates a new game.'''
    current_room = None # Class-level definition of this property.

    def __init__(self):
        print("Created a new Game object.")
        self.current_room = FirstRoom()

    @property
    def current_room(self):
        ''' Returns the current position of the actor.'''
        print("Getting the _current_room attribute for the Game object.")
        return self._current_room

    @current_room.setter   
    def set_room(self, new_room):
        ''' Sets the current_room property of the Game object.'''
        print("Setting the _current_room attribute for the Game object.")
        self._current_room = new_room

但是,当我运行此代码时,我得到以下输出:

>>> g = Game()
Created a new Game object.
Accessing the FirstRoom __init__ method.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/drew/Desktop/test.py", line 27, in __init__
    self.current_room = FirstRoom()
  File "/home/drew/Desktop/test.py", line 11, in __init__
    super.__init__()
TypeError: descriptor '__init__' of 'super' object needs an argument

我的代码中缺少什么才能使这种语法有效?我是否需要为“current_room”属性明确定义描述符? [这本书没有提到关于描述符的任何内容,至少不像你在这里找到的那​​样:Python Descriptors Demystified。]

3 个答案:

答案 0 :(得分:20)

使用super().__init__()代替super.__init__()

答案 1 :(得分:0)

超级错误实际上是将你打电话之前的打印件放到超级以下代码中:

class Room(object):
    ''' An area of the game's map.'''
    def __init__(self):
        print("Accessing the Room __init__ method.")


class FirstRoom(Room):
    ''' Just some room.'''

    def __init__(self):
        super().__init__()
        print("Accessing the FirstRoom __init__ method.")



class SecondRoom(Room):
    ''' Just some other room.'''

    def __init__(self):
        super().__init__()
        print("Accessing the SecondRoom __init__ method.")

您需要了解@property等工作原理。

Property python docs

从文档中,确保为其他功能提供与原始属性相同的名称

class Game(object):
    ''' Creates a new game.'''
    current_room = None  # Class-level definition of this property.

def __init__(self):
    print("Created a new Game object.")
    self._current_room = FirstRoom()

@property
def current_room(self, room): 
    ''' Returns the current position of the actor.'''
    print("Getting the _current_room attribute for the Game object.")
    return self._current_room


@current_room.setter # same function name as the property.
def current_room(self, new_room):# same name  as the property
    ''' Sets the current_room property of the Game object.'''
    print("Setting the _current_room attribute for the Game object.")
    self._current_room=new_room  

答案 2 :(得分:0)

这是工作代码:

class Room(object):
    ''' An area of the game's map.'''
    def __init__(self):
        print("Accessing the Room __init__ method.")


class FirstRoom(Room):
    ''' Just some room.'''
    def __init__(self):
        print("Accessing the FirstRoom __init__ method.")
        #super.__init__()
        super(FirstRoom, self).__init__()


class SecondRoom(Room):
    ''' Just some other room.'''
    def __init__(self):
        print("Accessing the SecondRoom __init__ method.")
        super(SecondRoom, self).__init__()
        #super.__init__()


class Game(object):
    ''' Creates a new game.'''
    _current_room = None # Class-level definition of this property.

    def __init__(self):
        print("Created a new Game object.")
        self._current_room = FirstRoom()

    @property
    def current_room(self):
        ''' Returns the current position of the actor.'''
        print("Getting the _current_room attribute for the Game object.")
        return self._current_room

    @current_room.setter   
    def set_room(self, new_room):
        ''' Sets the current_room property of the Game object.'''
        print("Setting the _current_room attribute for the Game object.")
        self._current_room = new_room

并且在运行时:

>>> g = Game()
Created a new Game object.
Accessing the FirstRoom __init__ method.
Accessing the Room __init__ method.
>>> 

希望这可以帮助你。