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    "### FreeObject\n",
    "\n",
    "#### What is FreeObject?\n",
    "\n",
    "Object 支持 . 操作来引用公共成员，Map 支持 [] 来引用字段。现定义一个类，其对象支持从 map 构造，可同时通过 [] 和 . 操作来引用字段成员。这个对象暂时称之为 FreeObject。\n",
    "\n",
    "FreeObject 是自动递归的，即自动支持 Object.a.b 和 Object['a']['b'] 的操作\n"
   ]
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    {
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     "text": [
      "free\n",
      "free\n",
      "None\n",
      "None\n"
     ]
    }
   ],
   "source": [
    "class FreeObject:\n",
    "    def __init__(self, dct={}):\n",
    "        self.__dict__.update(dct)\n",
    "        self.name = 'free'\n",
    "        \n",
    "    def __getitem__(self, name):\n",
    "        return self.__dict__.get(name)\n",
    "        \n",
    "    def __getattr__(self, name):\n",
    "        return self.__dict__.get(name)\n",
    "\n",
    "# test\n",
    "fo = FreeObject({'b': 20})\n",
    "print(fo.name)\n",
    "print(fo['name'])\n",
    "#\n",
    "print(fo.a) # None\n",
    "print(fo['a']) # None"
   ]
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    "#### V1\n",
    "\n",
    "上面的实现非常简单，但有两个问题\n",
    "1. 它仅支持平面结构，而不支持嵌套\n",
    "```python\n",
    "print(fo.a.c) # 要求 fo.a 返回的也必须是一个 FreeObject 对象\n",
    "```\n",
    "2. __init__() 之外，也可以任意的追加实例的属性，这可能把结构弄的很混乱\n",
    "```python\n",
    "fo.not_exists = 'exists'\n",
    "print(fo.not_exists) # 在构造函数之外添加了属性\n",
    "```\n"
   ]
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   "cell_type": "code",
   "execution_count": 47,
   "id": "52eee17a",
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    {
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     "text": [
      "passed\n",
      "passed\n",
      "{'a': 1, 'b': <__main__.FreeObject object at 0x7f467b9b6100>}\n",
      "None\n",
      "None\n",
      "exists\n"
     ]
    }
   ],
   "source": [
    "class FreeObject:\n",
    "    def __init__(self, dct={}):\n",
    "        self.__recursive_init(dct)\n",
    "    \n",
    "    def __recursive_init(self, dct={}):\n",
    "        '''\n",
    "        递归初始化 FreeObject\n",
    "        '''\n",
    "        self.__dict__.update(dct)\n",
    "        for k, v in dct.items():\n",
    "            if type(v) is dict:\n",
    "                self.__dict__[k] = FreeObject(v)\n",
    "            \n",
    "    def __getitem__(self, name):\n",
    "        return self.__dict__.get(name)\n",
    "        \n",
    "    def __getattr__(self, name):\n",
    "        return self.__dict__.get(name)\n",
    "    \n",
    "    def __setattr__(self, name, value):\n",
    "        pass\n",
    "    \n",
    "    def __setitem__(self, name, value):\n",
    "        pass\n",
    "\n",
    "fo = FreeObject({'a': 1, 'b': {'c': 1, 'd': {'test': 'passed'}}})\n",
    "# issue1\n",
    "print(fo.b.d.test)\n",
    "print(fo['b']['d']['test'])\n",
    "print(fo.__dict__)\n",
    "\n",
    "# issue2\n",
    "fo.not_exists = 'exists'\n",
    "print(fo.not_exists)\n",
    "fo['not_exists'] = 'exists'\n",
    "print(fo.not_exists)\n",
    "\n",
    "# new issues\n",
    "fo.__dict__['not_exists'] = 'exists'\n",
    "print(fo.not_exists)"
   ]
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   "id": "3dfc53df",
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   "source": [
    "### v2\n",
    "\n",
    "上面新的实现中，初步解决了 V1 中的两个问题。但还存在直接访问修改实例的 __dict__ 属性的方法来侵入对象内部。\n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7815e12f",
   "metadata": {},
   "source": [
    "**To be Continue**"
   ]
  },
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   "cell_type": "code",
   "execution_count": null,
   "id": "ccf518a7",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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