Solution/Day_01_Solution_v2.ipynb

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    "# [作業目標]\n",
    "\n",
    "1. [簡答題] 請問下列兩種將 Array 轉換成 List 的方式有何不同？\n",
    "\n",
    "```\n",
    "print('list(a): ', list(a))\n",
    "print('tolist(): ', a.tolist())\n",
    "```\n",
    "\n",
    "2. 請試著在程式中印出以下三個 NdArray 的屬性？（屬性：ndim、shape、size、dtype、itemsize、length、type）\n",
    "\n",
    "```\n",
    "a = np.random.randint(10, size=6) \n",
    "b = np.random.randint(10, size=(3,4)) \n",
    "c = np.random.randint(10, size=(2,3,2)) \n",
    "```\n",
    "\n",
    "3. 如何利用 list(...) 實現 a.tolist() 的效果？試著用程式實作。\n"
   ]
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   "source": [
    "# 作業 "
   ]
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   "source": [
    "### 1. [簡答題] 請問下列兩種將 Array 轉換成 List 的方式有何不同？\n",
    "\n",
    "```\n",
    "print('list(a): ', list(a))\n",
    "print('tolist(): ', a.tolist())\n",
    "```\n"
   ]
  },
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     "text": [
      "list(a):  [3, 1, 4, 7, 4, 5]\n",
      "a.tolist():  [3, 1, 4, 7, 4, 5]\n",
      "list(b):  [array([8, 1]), array([7, 5]), array([3, 9])]\n",
      "b.tolist():  [[8, 1], [7, 5], [3, 9]]\n"
     ]
    }
   ],
   "source": [
    "import numpy as np\n",
    "\n",
    "a = np.random.randint(10, size=6) \n",
    "\n",
    "print('list(a): ', list(a))\n",
    "print('a.tolist(): ', a.tolist())\n",
    "\n",
    "b = np.random.randint(10, size=6).reshape(3,2)\n",
    "\n",
    "print('list(b): ', list(b))\n",
    "print('b.tolist(): ', b.tolist())\n",
    "\n"
   ]
  },
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    {
     "data": {
      "text/plain": [
       "'\\nlist(a) 只會把第一層的元素轉換成 List，多層的話只有第一層會轉；tolist() 才能達成多層的型態轉換。\\n'"
      ]
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   ],
   "source": [
    "'''\n",
    "list(a) 只會把第一層的元素轉換成 List，多層的話只有第一層會轉；tolist() 才能達成多層的型態轉換。\n",
    "'''"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "id": "mcdoyiaFaXA8"
   },
   "source": [
    "### 2. 請試著在程式中印出以下三個 NdArray 的屬性並且解釋結果？（屬性：ndim、shape、size、dtype、itemsize、length、type）\n",
    "\n",
    "```\n",
    "a = np.random.randint(10, size=6) \n",
    "b = np.random.randint(10, size=(3,4)) \n",
    "c = np.random.randint(10, size=(2,3,2)) \n",
    "```"
   ]
  },
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     "text": [
      "[9 8 0 0 5 5]\n",
      "1\n",
      "(6,)\n",
      "6\n",
      "int64\n",
      "8\n",
      "6\n",
      "<class 'numpy.ndarray'>\n"
     ]
    }
   ],
   "source": [
    "# 參考解答\n",
    "\n",
    "import numpy as np\n",
    "\n",
    "a = np.random.randint(10, size=6) \n",
    "\n",
    "print(a)\n",
    "\n",
    "print(a.ndim)\n",
    "print(a.shape)\n",
    "print(a.size)\n",
    "print(a.dtype)\n",
    "print(a.itemsize)\n",
    "print(len(a))\n",
    "print(type(a))"
   ]
  },
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     "text": [
      "[[2 9 5 0]\n",
      " [4 3 3 5]\n",
      " [0 0 2 8]]\n",
      "2\n",
      "(3, 4)\n",
      "12\n",
      "int64\n",
      "8\n",
      "3\n",
      "<class 'numpy.ndarray'>\n"
     ]
    }
   ],
   "source": [
    "b = np.random.randint(10, size=(3,4)) \n",
    "\n",
    "print(b)\n",
    "\n",
    "print(b.ndim)\n",
    "print(b.shape)\n",
    "print(b.size)\n",
    "print(b.dtype)\n",
    "print(b.itemsize)\n",
    "print(len(b))\n",
    "print(type(b))"
   ]
  },
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     "text": [
      "[[[3 9]\n",
      "  [4 1]\n",
      "  [8 2]]\n",
      "\n",
      " [[5 2]\n",
      "  [4 3]\n",
      "  [9 1]]]\n",
      "3\n",
      "(2, 3, 2)\n",
      "12\n",
      "int64\n",
      "8\n",
      "2\n",
      "<class 'numpy.ndarray'>\n"
     ]
    }
   ],
   "source": [
    "c = np.random.randint(10, size=(2,3,2)) \n",
    "\n",
    "print(c)\n",
    "\n",
    "print(c.ndim)\n",
    "print(c.shape)\n",
    "print(c.size)\n",
    "print(c.dtype)\n",
    "print(c.itemsize)\n",
    "print(len(c))\n",
    "print(type(c))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "id": "0pyQ9W3faXBB"
   },
   "source": [
    "### 3. 如何利用 list(...) 實現 a.tolist() 的效果？試著用程式實作。\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
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   "outputs": [
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     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[7, 4, 4, 5, 4, 7]\n",
      "[7, 4, 4, 5, 4, 7]\n"
     ]
    }
   ],
   "source": [
    "a = np.random.randint(10, size=6) \n",
    "\n",
    "print(a.tolist())\n",
    "print(list(a))\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "id": "dfrvGkPQaXBD",
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     "name": "stdout",
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     "text": [
      "[[9, 3, 6, 2], [9, 3, 9, 2], [6, 5, 8, 1]]\n",
      "[array([9, 3, 6, 2]), array([9, 3, 9, 2]), array([6, 5, 8, 1])]\n"
     ]
    }
   ],
   "source": [
    "b = np.random.randint(10, size=(3,4)) \n",
    "\n",
    "print(b.tolist())\n",
    "print(list(b))\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "id": "kCLPSApKaXBF",
    "outputId": "cb007363-f28a-44eb-aa00-2ae112aea22e"
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     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[[7, 6], [1, 9], [4, 6]], [[3, 9], [0, 5], [3, 8]]]\n",
      "[array([[7, 6],\n",
      "       [1, 9],\n",
      "       [4, 6]]), array([[3, 9],\n",
      "       [0, 5],\n",
      "       [3, 8]])]\n"
     ]
    }
   ],
   "source": [
    "c = np.random.randint(10, size=(2,3,2)) \n",
    "\n",
    "print(c.tolist())\n",
    "print(list(c))\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {
    "id": "JybfqL5eaXBF",
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[7, 4, 4, 5, 4, 7]\n",
      "[[9, 3, 6, 2], [9, 3, 9, 2], [6, 5, 8, 1]]\n",
      "[[[7, 6], [1, 9], [4, 6]], [[3, 9], [0, 5], [3, 8]]]\n"
     ]
    }
   ],
   "source": [
    "## 簡單版\n",
    "\n",
    "def tolist(iterable):\n",
    "    if type(iterable) != np.ndarray:\n",
    "        return iterable\n",
    "    newlist = []\n",
    "    for obj in iterable:\n",
    "        newlist.append(tolist(obj))\n",
    "    return list(newlist)\n",
    "\n",
    "print(tolist(a))\n",
    "print(tolist(b))\n",
    "print(tolist(c))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {
    "id": "o7r30s0OaXBG",
    "outputId": "124c929c-6f25-4ea3-cfef-52febef6c084"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[7, 4, 4, 5, 4, 7]\n",
      "[[9, 3, 6, 2], [9, 3, 9, 2], [6, 5, 8, 1]]\n",
      "[[[7, 6], [1, 9], [4, 6]], [[3, 9], [0, 5], [3, 8]]]\n"
     ]
    }
   ],
   "source": [
    "## 進階版\n",
    "\n",
    "def tolist(iterable):\n",
    "    if type(iterable) != np.ndarray:\n",
    "        return iterable\n",
    "    return [tolist(obj) for obj in iterable]\n",
    "\n",
    "print(tolist(a))\n",
    "print(tolist(b))\n",
    "print(tolist(c))"
   ]
  },
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   "execution_count": null,
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  },
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   "cell_type": "code",
   "execution_count": null,
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