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   "cell_type": "code",
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   "source": [
    "# Python list -> sublist\n",
    "\n",
    "# creating a sublist, such as list[10: 14], duplicates the data;\n",
    "# they then exist in memory twice.\n",
    "# modifying the sublist does not affect the original list.\n",
    "\n",
    "list = [x*x for x in range(16)]\n",
    "sublist = list[10: 14]\n",
    "\n",
    "print(\"list:\", list, sep=\"\\t\\t\")\n",
    "print(\"sublist:\", sublist, sep=\"\\t\", end=\"\\n\\n\")\n",
    "\n",
    "for i in range(len(sublist)):\n",
    "    sublist[i] -= 1\n",
    "\n",
    "print(\"list:\", list, sep=\"\\t\\t\")\n",
    "print(\"sublist:\", sublist, sep=\"\\t\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# numpy array -> view\n",
    "\n",
    "# creating an array view, such as array[10: 14],\n",
    "# creates a new reference to part of the region in memory allocated for the array;\n",
    "# the data are not copied, they still exist in memory only once.\n",
    "# therefore, modifications done to the view are reflected in the content of the original array.\n",
    "\n",
    "import numpy as np\n",
    "\n",
    "array = np.array([x*x for x in range(16)])\n",
    "view = array[10: 14]\n",
    "\n",
    "print(\"array:\", array, sep=\"\\t\")\n",
    "print(\"view:\", view, sep=\"\\t\", end=\"\\n\\n\")\n",
    "\n",
    "for i in range(len(view)):\n",
    "    view[i] -= 1\n",
    "\n",
    "print(\"array:\", array, sep=\"\\t\")\n",
    "print(\"view:\", view, sep=\"\\t\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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