Question

我一直试图掌握PyYAML，因为我喜欢它的可读性，并希望在一些开源项目中使用它，我正在替代JSON。

但是，我很难理解如何使用合成来构造对象。我打开了这个问题：PyYAML - how to deal with compositon它似乎在阅读信息方面起作用，但不是在完整程序的上下文中。

以下是我正在尝试YAMLify的一个简单示例：

import yaml
import data

class DungeonObject(yaml.YAMLObject):
    yaml_tag = u'!DungeonObject'
    def __init__(self, x, y, char, name, blocks=False, fighter=None):
        self.x = x
        self.y = y
        self.char = char
        self.name = name
        self.blocks = blocks

        self.fighter = fighter
        if self.fighter:
            self.fighter.owner = self


    def __repr__(self):
        return "%s(x=%r, y=%r, char=%r, name=%r, blocks=%r fighter=%r)" % (self.__class__.__name__, self.x, self.y, self.char, self.name, self.blocks, self.fighter)

class Fighter(yaml.YAMLObject):
    yaml_tag = u'!Fighter'
    #combat-related properties and methods (monster, player, NPC).
    def __init__(self, hp, defense, strength):
        self.hp = hp
        self.base_defense = defense
        self.base_strength = strength
    def __repr__(self):
        return "%s(hp=%r, defense=%r, strength=%r)" % (self.__class__.__name__, self.hp, self.defense, self.strength)


monsters = {DungeonObject.name : DungeonObject for DungeonObject in yaml.load_all(data.monsterdata)}
print (monsters)

我的YAML文件：

monsterdata = """
---
!Fighter &fighter_component
    hp: 20
    defense: 0
    strength: 4
!DungeonObject
    x: x
    y: y
    char: 'o'
    name: 'orc'
    blocks: True
    fighter: fighter_component
---
!Fighter &fighter_component
    hp: 9
    defense: 0
    strength: 10
!DungeonObject
    x: x
    y: y
    char: 't'
    name: 'troll'
    blocks: True
    fighter: fighter_component
"""

有了这个，我收到了错误： 第32行，in monsters = {DungeonObject.name：DungeonObject中的DungeonObject，位于yaml.load_all（data.monsterdata）} AttributeError：'Fighter'对象没有属性'name'

Answer 1

每个文档都应包含由Fighter和DungeonObject组成的序列/列表。前者没有名称，所以你应该过滤DungeonObjects，它们是DungeonObject类型而不是Fighter类型。

有点令人困惑的是你也使用变量DungeonObject，所以尝试使用dungeon_object作为变量：

from ruamel import yaml

monsterdata = """
---
- !Fighter &fighter_component
    hp: 20
    defense: 0
    strength: 4
- !DungeonObject
    x: x
    y: y
    char: 'o'
    name: 'orc'
    blocks: True
    fighter: fighter_component
---
- !Fighter &fighter_component
    hp: 9
    defense: 0
    strength: 10
- !DungeonObject
    x: x
    y: y
    char: 't'
    name: 'troll'
    blocks: True
    fighter: fighter_component
"""


class DungeonObject(yaml.YAMLObject):
    yaml_tag = u'!DungeonObject'

    def __init__(self, x, y, char, name, blocks=False, fighter=None):
        self.x = x
        self.y = y
        self.char = char
        self.name = name
        self.blocks = blocks

        self.fighter = fighter
        if self.fighter:
            self.fighter.owner = self

    def __repr__(self):
        return "{}(x={!r}, y={!r}, char={!r}, name={!r}, blocks={!r} fighter={!r})".format(
            self.__class__.__name__, self.x, self.y, self.char, self.name,
            self.blocks, self.fighter)


class Fighter(yaml.YAMLObject):
    yaml_tag = u'!Fighter'
    # combat-related properties and methods (monster, player, NPC).

    def __init__(self, hp, defense, strength):
        self.hp = hp
        self.base_defense = defense
        self.base_strength = strength

    def __repr__(self):
        return "{}(hp={!r}, defense={!r}, strength={!r})".format(
            self.__class__.__name__, self.hp, self.defense, self.strength)

monsters = {}
for doc in yaml.load_all(monsterdata, Loader=yaml.Loader):
    for dungeon_object in doc:
        if isinstance(dungeon_object, DungeonObject):
            monsters[dungeon_object.name] = dungeon_object

print (monsters)

给出了：

{'orc': DungeonObject(x='x', y='y', char='o', name='orc', blocks=True fighter='fighter_component'), 'troll': DungeonObject(x='x', y='y', char='t', name='troll', blocks=True fighter='fighter_component')}

我更新了__repr__以使用更现代的.format()方法。由于我使用的是ruamel.yaml（它是PyYAML功能的超集并向后兼容），我需要明确指定Loader以在使用默认加载器时禁止load_all不安全的警告。（免责声明：我是该软件包的开发者）

PyYAML和组合，属性错误

1 个答案: