Python libtcod奇怪描述错误

Question

我很惊讶这没有崩溃，但我真的不确定这里发生了什么。在鼠标悬停+键按下'd‘时，应调出鼠标下的对象菜单(确实如此)。当选择一个对象时，它应该从该对象描述中打印一条消息到控制台。但它不会，它会打印像<__main__.Object instance at 0x02AE1800>这样的东西。

下面是相关的代码

def menu(header, options, width):
    if len(options) > 26: raise ValueError('Cannot have a menu with more than 26 options.'

    #calculate the total height for the header (afer auto wrap) and one line per option
    header_height = libtcod.console_get_height_rect(con, 0, 0, width, SCREEN_HEIGHT, header)
    height = len(options) + header_height

    #create an off-screen console that represents the menu's window
    window = libtcod.console_new(width, height)

    #print the header, with auto wrap, baby.
    libtcod.console_set_default_foreground(window, libtcod.white)
    libtcod.console_print_rect_ex(window, 0, 0, width, height, libtcod.BKGND_NONE, libtcod.LEFT, header)

    #print all the options
    y = header_height
    letter_index = ord('a')
    for option_text in options:
        text = '(' + chr(letter_index) + ') ' + option_text
        libtcod.console_print_ex(window, 0, y, libtcod.BKGND_NONE, libtcod.LEFT, text)
        y += 1
        letter_index += 1

    #blit the contents of "window" to the root console
    x = SCREEN_WIDTH/2 - width/2
    y = SCREEN_HEIGHT   /2 - height/2
    libtcod.console_blit(window, 0, 0, width, height, 0, x, y, 1.0, 0.7)

    #present the root console to the player and wait for keypress
    libtcod.console_flush()
    key = libtcod.console_wait_for_keypress(True)

    #convert the ASCII code to an index; if it corresponds to an option, return it
    index = key.c - ord('a')
    if index >= 0 and index < len(options): return index
    return None

def handle_keys():
    global keys;

            if key_char == 'd':
                #show the description menu, if an item is selected, describe it.
                chosen_object = description_menu('Press the key next to an object to see its description.\n')
                if chosen_object is not None:
                    chosen_object.describe()
                else:
                    return 'cancelled'

            return 'didnt-take-turn'

def description_menu(header): 

    global mouse

    #return a string with the names of all objects under the mouse
    (x, y) = (mouse.cx, mouse.cy)

    #create a list with the names of all objects at the mouse's coordinates and in FOV
    names = [obj for obj in objects if obj.x == x and obj.y == y and libtcod.map_is_in_fov(fov_map, obj.x, obj.y) and obj.description is not None]

    #show a menu with each object under the mouse as an option
    if len(names) == 0:
        options = ['There is nothing here.']
    else:
        options = [object.name for object in names]

    index = menu(header, options, INVENTORY_WIDTH)

    #if an item was chosen, return it
    if index is None or len(names) == 0: return None
    return names[index]

Class Object:
    #this is a generic object: the player, a monster, an item, the stairs...
    #it's always represented by a character on screen.
    def __init__(self, x, y, char, name, color, blocks=False, fighter=None, ai=None, item=None, description=None):
        self.x = x
        self.y = y
        self.char = char
        self.name = name
        self.color = color
        self.blocks = blocks
        self.fighter = fighter
        if self.fighter: #let the fighter component know who owns it
            self.fighter.owner = self
        self.ai = ai
        if self.ai: #let the ai component know who owns it
            self.ai.owner = self
        self.item = item
        if self.item: #let the item component know who owns it, like a bitch
            self.item.owner = self
        self.description = self
        if self.description: #let the description component know who owns it
            self.description.owner = self

    def describe(self):
        #describe this object
        if self.description is None:
            message('The ' + self.owner.name + ' cannot be described.')
        else:
            message(str(self.description), libtcod.white)`

Answer 1

我的猜测是，当您确实想要传递一个包含一些易于理解的信息的字符串时，您会将Object实例的字符串表示传递给message。str方法调用Object.__str__ (python的magic methods之一) Object.__str__没有在您的代码中定义，所以str默认调用Object.__repr__，这是您获取<__main__.Object instance at 0x02AE1800>的地方。

尝试定义Object.__str__，使其返回一个字符串，其中包含您希望在print-ing时显示的信息。

例如：

Class Object:
    def __init__(self, name, x, y):
        self.name = name
        self.x = x
        self.y = y

    def __str__(self):
        return("Object " + self.name + " is at position [" + self.x + "," + self.y + "]")

最后，我不能确定问题出在哪里，因为我们没有message方法的定义。您应该包含该方法的代码，以便我们能够更好地了解发生了什么。祝好运!