{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float]\n",
    "    number: int"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass\n",
    "\n",
    "@dataclass(repr=False, eq=True, order=False)\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float]\n",
    "    number: int"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float] = 0\n",
    "    number: int = 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass, field\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float] = 0\n",
    "    number: int = 0\n",
    "    categories: t.List[str] = field(default_factory=list)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass, field\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float] = field(default=0)\n",
    "    number: int = field(default=0)\n",
    "    categories: t.List[str] = field(default_factory=list)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "Item(name='iPhone 14', price=6999, number=1000, categories=[Category(level=1, name='')])"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import typing as t\n",
    "from dataclasses import dataclass, field\n",
    "\n",
    "\n",
    "@dataclass\n",
    "class Category:\n",
    "    level: int = 1\n",
    "    name: str = \"\"\n",
    "\n",
    "\n",
    "def default_categories():\n",
    "    return [Category()]\n",
    "\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float] = field(default=0)\n",
    "    number: int = field(default=0)\n",
    "    categories: t.List[Category] = field(default_factory=default_categories)\n",
    "\n",
    "\n",
    "Item(\"iPhone 14\", price=6999, number=1000)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "import sys\n",
    "\n",
    "if sys.version_info >= (3, 10):\n",
    "    from dataclasses import KW_ONLY\n",
    "\n",
    "    import typing as t\n",
    "    from dataclasses import KW_ONLY, dataclass, field\n",
    "\n",
    "\n",
    "    @dataclass\n",
    "    class Category:\n",
    "        level: int = 1\n",
    "        name: str = \"\"\n",
    "\n",
    "\n",
    "    def default_categories():\n",
    "        return [Category()]\n",
    "\n",
    "\n",
    "    @dataclass\n",
    "    class Item:\n",
    "        name: str\n",
    "        _: KW_ONLY\n",
    "        price: t.Union[int, float] = field(default=0)\n",
    "        number: int = field(default=0)\n",
    "        categories: t.List[Category] = field(default_factory=default_categories)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "import typing as t\n",
    "from dataclasses import asdict, astuple, dataclass, field\n",
    "\n",
    "\n",
    "@dataclass\n",
    "class Category:\n",
    "    level: int = 1\n",
    "    name: str = \"\"\n",
    "\n",
    "\n",
    "def default_categories():\n",
    "    return [Category()]\n",
    "\n",
    "\n",
    "@dataclass\n",
    "class Item:\n",
    "    name: str\n",
    "    price: t.Union[int, float] = field(default=0)\n",
    "    number: int = field(default=0)\n",
    "    categories: t.List[Category] = field(default_factory=default_categories)\n",
    "\n",
    "\n",
    "item = Item(\"iPhone 14\", price=6999, number=1000)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "('iPhone 14', 6999, 1000, [(1, '')])"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "astuple(item)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'name': 'iPhone 14',\n",
       " 'price': 6999,\n",
       " 'number': 1000,\n",
       " 'categories': [{'level': 1, 'name': ''}]}"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "asdict(item)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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