05 自建類別和字串格式化進階.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "![Class 的使用](images/class.png)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "很粗略的說, 我們可以把 `Class` 想成一個「自訂資料型態」的方法。Python 什麼東西都是「物件」, 而在我們定義一個字串時, 其實是定義了一個「字串這個類別 (class)」的「實例 (instance)」。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "st = \"hello world\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這裡 `st` 是「字串」這個類別的一個實例。\n",
    "\n",
    "![檢查有什麼可用的 method](images/method.png)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "所謂的方法 (method), 就是一個類別 (如字串) 中定義, 可以作用在這個實例 (變數) 身上的函式。\n",
    "\n",
    "再一次, 我們可以把定一個 `Class` 看成自己定義新的資料型態的方法。比如說, 我們想定義一個「樸克牌 Class」, 也許可以這樣做..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Card:\n",
    "    suit = 3\n",
    "    rank = 5"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "我們來定義一張牌 `card01`。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "card01 = Card()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "card01.suit = 2\n",
    "card01.rank = 5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "2"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01.suit"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01.rank"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "我們甚至可以檢查 `card01` 的資料型態。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "__main__.Card"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "type(card01)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "我們可以再定義新的牌。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [],
   "source": [
    "card02 = Card()\n",
    "\n",
    "card02.suit = 3\n",
    "card02.rank = 10"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "但這樣子也太麻煩了, 難道不能這樣:\n",
    "    \n",
    "    card02 = Card(3, 10)\n",
    "    \n",
    "就定義一張牌? 答案當然是肯定的! 這時要動用 Python 的「特殊方法」, 這些在 Class 中使用的特殊方法, 都有一個特殊的命名方式, 那就是...\n",
    "\n",
    "![special method](images/special_method.png)\n",
    "\n",
    "每個特殊方法都有特定使用場合, 比如說 `__init__` 就是在定義一個 class 的實例時會呼叫的函式。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Card:\n",
    "\n",
    "    def __init__(self, s, r):\n",
    "        self.suit = s\n",
    "        self.rank = r"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這裡要解釋的是, 所有在類別定義的方法 (函式), 一定要引用實例自己本身。這也是初學者最弄不清楚的地方。\n",
    "\n",
    "而實例在定義 class 時根本也還沒有定義, 我們怎知該叫什麼呢? 於是一般都很聰明的稱為 `self`。這其實不一定非叫 `self`, 只是高手們大家都這樣叫, 我們也這樣叫看起來就好像很有涵養的樣子。\n",
    "\n",
    "這樣子定義好, 我們就可以快速的定義一張樸克牌!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [],
   "source": [
    "card01 = Card(2, 3)\n",
    "card02 = Card(3, 10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "2"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01.suit"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01.rank"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "我們自己可能知道, suit 代表花色, 有四種所以是 0, 1, 2, 3。可是一般人怎麼知道這是什麼呢? 我們就來第一個自己寫的 class 方法, 用途就是印出花色、牌面點數。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Card:\n",
    "    SUITS = [\"♣\", \"♦\", \"♥\", \"♠\"]\n",
    "    RANKS = ['A', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K']\n",
    "    \n",
    "    def __init__(self, s, r):\n",
    "        self.suit = s\n",
    "        self.rank = r\n",
    "        \n",
    "    def show(self):\n",
    "        print(self.SUITS[self.suit] + self.RANKS[self.rank])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [],
   "source": [
    "card01 = Card(2, 3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "♥4\n"
     ]
    }
   ],
   "source": [
    "card01.show()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這是不是看來順眼多了? 不過當我們想看 `card01` 內容..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<__main__.Card at 0x7fbbc80fdf28>"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "甚至印出 `card01` 內容..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "<__main__.Card object at 0x7fbbc80fdf28>\n"
     ]
    }
   ],
   "source": [
    "print(card01)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "為什麼會這樣呢? 因為我們根本沒有定義該怎麼表示 Card 這個類別裡的東西。要做到這件事, 要用另一個特殊方法:\n",
    "\n",
    "    __repr__"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Card:\n",
    "    SUITS = [\"♣\", \"♦\", \"♥\", \"♠\"]\n",
    "    RANKS = ['A', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K']\n",
    "    \n",
    "    def __init__(self, s, r):\n",
    "        self.suit = s\n",
    "        self.rank = r\n",
    "    \n",
    "    def __repr__(self):\n",
    "        return self.SUITS[self.suit] + self.RANKS[self.rank]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [],
   "source": [
    "card01 = Card(2, 3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "♥4"
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "card01"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "♥4\n"
     ]
    }
   ],
   "source": [
    "print(card01)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "傑克, 這真的太神奇了!\n",
    "\n",
    "不過這裡要說明一點, 其實很多時候你不一定非要把程式寫成 Class, 可以用一個或多個函式來做到你想做的事。\n",
    "\n",
    "我們這裡介紹 Class, 最重要的其實是讓大家看懂別人用 Class 寫的程式。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "![string formating](images/format.png)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### `print` 不換行可以嗎?\n",
    "\n",
    "我們想印出一堆數字 (或文字)..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n",
      "6\n",
      "7\n",
      "8\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "for i in range(10):\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這拖太長了, 可以不要換行嗎? 我們想到可愛的逗號..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n",
      "6\n",
      "7\n",
      "8\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "for i in range(10):\n",
    "    print(i,)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這是在搞笑嗎?\n",
    "\n",
    "原來, Python 印出來的字串要「某個方式接續」是這樣做..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0, 1, 2, 3, 4, 5, 6, 7, 8, 9, "
     ]
    }
   ],
   "source": [
    "for i in range(10):\n",
    "    print(i, end=', ')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這時果然被抓包, 說 9 的後面好像不該有逗點。對, 這都要例外處理。\n",
    "\n",
    "雖然不是我們的重點, 不過為了老師的威信 (?), 所以還是介紹其中一種方式。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0, 1, 2, 3, 4, 5, 6, 7, 8, 9\n"
     ]
    }
   ],
   "source": [
    "print(', '.join(map(str, range(10))))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "附註: 這要「背」還有點難。不過理解在做什麼, 就自己也會寫出看來很可怕的東西。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 格式化的三種方式\n",
    "\n",
    "之前我們要控制一堆字串印出來, 就是要用 \"+\" 合在一起..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [],
   "source": [
    "name = \"炎龍\"\n",
    "age = 25"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "你好, 我是炎龍, 今年 25 歲。\n"
     ]
    }
   ],
   "source": [
    "print(\"你好, 我是\" + name + \", 今年 \" + str(25) + \" 歲。\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這實在有夠難打的, 所以 Python 提供了格式化字串的方法, 而且有三種!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 方法 1: 最老派的方式\n",
    "\n",
    "在要印出字串的地方打上 `%s`, 要印出整數的地方打上 `%d`, 要印出點數打上 `%f`..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [],
   "source": [
    "message = \"你好, 我是%s, 今年 %d 歲。\" % (name, age)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "你好, 我是炎龍, 今年 25 歲。\n"
     ]
    }
   ],
   "source": [
    "print(message)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "哦, 好像不錯耶! 不過要記得 `%s` 啦, `%d` 啦, `%f` 等等是什麼意思好像有點討厭。"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 方法 2: `format`\n",
    "\n",
    "直接在要填入東西的地方, 放上 `{}`, 不用說這是字串啦、數字啦還是什麼的。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [],
   "source": [
    "message = \"你好, 我是{}, 今年 {} 歲。\".format(name, age)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "你好, 我是炎龍, 今年 25 歲。\n"
     ]
    }
   ],
   "source": [
    "print(message)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "這好像更好一點, 不過有更方便的嗎?"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 方法 3: 全新的 `f-string`\n",
    "\n",
    "`f-string` 是 Python 3.6 才有的方法。直接填入要什麼就有什麼..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {},
   "outputs": [],
   "source": [
    "message = f\"你好, 我是{name}, 今年 {age} 歲。\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "你好, 我是炎龍, 今年 25 歲。\n"
     ]
    }
   ],
   "source": [
    "print(message)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 更完整的控制 (浮點數篇)\n",
    "\n",
    "我們 Google 一下, 發現 1 美元合台幣 31.0665134 元。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [],
   "source": [
    "c = 31.0665134"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 美元合台灣 31.0665134 元。\n"
     ]
    }
   ],
   "source": [
    "print(f\"1 美元合台灣 {c} 元。\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "更炫的事是, 我們可以控制只印出小數點後 2 位。這時的 `f` (浮點數) 又出現了。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 美元合台灣 31.07 元。\n"
     ]
    }
   ],
   "source": [
    "print(f\"1 美元合台灣 {c:.2f} 元。\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "注意還自動四捨五入! 再來我們看看以下這個例子。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 美元合台灣      31.07 元。\n"
     ]
    }
   ],
   "source": [
    "print(f\"1 美元合台灣 {c:10.2f} 元。\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "看出來發生什麼事了嗎?\n",
    "\n",
    "![number formating](images/number_formating.png)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 更完整的控制 (對齊補滿篇)\n",
    "\n",
    "我們其實還可以控制靠左靠右的對齊..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "        *■\n"
     ]
    }
   ],
   "source": [
    "star = \"*\"\n",
    "print(f\"{star:>9s}■\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "靠左。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "*        ■\n"
     ]
    }
   ],
   "source": [
    "star = \"*\"\n",
    "print(f\"{star:<9s}■\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "置中。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 46,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "    *    ■\n"
     ]
    }
   ],
   "source": [
    "star = \"*\"\n",
    "print(f\"{star:^9s}■\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "還可以用指定符號填滿空格。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "........*■\n"
     ]
    }
   ],
   "source": [
    "star = \"*\"\n",
    "print(f\"{star:.>9s}■\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "常見的應用是數字前要補 0。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "metadata": {},
   "outputs": [],
   "source": [
    "m = str(3)\n",
    "d = str(8)\n",
    "\n",
    "m_str = f\"{m:0>2s}\"\n",
    "d_str = f\"{d:0>2s}\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 53,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'03'"
      ]
     },
     "execution_count": 53,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "m_str"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 54,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'08'"
      ]
     },
     "execution_count": 54,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "d_str"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "當然, 還可以更快的..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 57,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'03'"
      ]
     },
     "execution_count": 57,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "m.zfill(2)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "利用置中的耍寶小應用。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 58,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "      *      \n",
      "     ***     \n",
      "    *****    \n",
      "   *******   \n",
      "  *********  \n",
      " *********** \n",
      "*************\n"
     ]
    }
   ],
   "source": [
    "for i in range(1, 14, 2):\n",
    "    stars = \"*\" * i\n",
    "    print(f'{stars:^13s}')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "![文青機器人](images/poem.png)\n",
    "\n",
    "我們讓 Python 寫首詩吧。\n",
    "\n",
    "去收集一些你覺得容易在詩裡出現的字眼, 做成一個串列。接著, 你可以亂數決定幾句的詩, 比如說 2-7 句。同時也可以亂數決定每句各用多少詞, 再隨機選取你選的字..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 59,
   "metadata": {},
   "outputs": [],
   "source": [
    "st = '''\n",
    "我\n",
    "我的\n",
    "眼睛\n",
    "妳\n",
    "妳的\n",
    "心\n",
    "溫柔\n",
    "日子\n",
    "雨\n",
    "風\n",
    "天空\n",
    "雲\n",
    "等待\n",
    "哭泣\n",
    "戀愛\n",
    "相遇\n",
    "分離\n",
    "忘記\n",
    "心醉\n",
    "驀然\n",
    "吹過\n",
    "思念\n",
    "靈魂\n",
    "停止\n",
    "'''"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 60,
   "metadata": {},
   "outputs": [],
   "source": [
    "words = st.split('\\n')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 61,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['',\n",
       " '我',\n",
       " '我的',\n",
       " '眼睛',\n",
       " '妳',\n",
       " '妳的',\n",
       " '心',\n",
       " '溫柔',\n",
       " '日子',\n",
       " '雨',\n",
       " '風',\n",
       " '天空',\n",
       " '雲',\n",
       " '等待',\n",
       " '哭泣',\n",
       " '戀愛',\n",
       " '相遇',\n",
       " '分離',\n",
       " '忘記',\n",
       " '心醉',\n",
       " '驀然',\n",
       " '吹過',\n",
       " '思念',\n",
       " '靈魂',\n",
       " '停止',\n",
       " '']"
      ]
     },
     "execution_count": 61,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "words"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 62,
   "metadata": {},
   "outputs": [],
   "source": [
    "from random import randint, choices, sample"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 65,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "驀然 心 戀愛 吹過\n",
      "靈魂 日子 心醉\n"
     ]
    }
   ],
   "source": [
    "n = randint(2, 7) # 決定有幾句\n",
    "\n",
    "for i in range(n):\n",
    "    m = randint(2, 5) # 決定每句的長度\n",
    "    sentence = sample(words, m)\n",
    "    print(\" \".join(sentence))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "然後我們改成函數。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 66,
   "metadata": {},
   "outputs": [],
   "source": [
    "def poem():\n",
    "    n = randint(2, 7) # 決定有幾句\n",
    "\n",
    "    for i in range(n):\n",
    "        m = randint(2, 5) # 決定每句的長度\n",
    "        sentence = sample(words, m)\n",
    "        print(\" \".join(sentence))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 67,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "靈魂 風 心 停止 心醉\n",
      "戀愛 停止\n",
      "吹過 停止 靈魂 我的 妳的\n"
     ]
    }
   ],
   "source": [
    "poem()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "於是我們就可以一直寫詩..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 68,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "哭泣 戀愛 驀然 我的\n",
      "日子 眼睛 \n",
      "妳的 等待 我\n",
      "思念 哭泣 心 風 \n",
      "戀愛 忘記\n",
      "眼睛 天空 心 風 吹過\n"
     ]
    }
   ],
   "source": [
    "poem()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 69,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "我的 分離\n",
      "我 我的 天空 等待\n",
      "我 思念 日子 心醉\n",
      "心醉 溫柔  忘記 \n",
      "戀愛 風  相遇 溫柔\n",
      "妳  \n",
      "溫柔 停止 戀愛\n"
     ]
    }
   ],
   "source": [
    "poem()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "用之前學的存檔起來!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 70,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The following commands were written to file `poem.py`:\n",
      "from random import randint, choices, sample\n",
      "st = '''\n",
      "我\n",
      "我的\n",
      "眼睛\n",
      "妳\n",
      "妳的\n",
      "心\n",
      "溫柔\n",
      "日子\n",
      "雨\n",
      "風\n",
      "天空\n",
      "雲\n",
      "等待\n",
      "哭泣\n",
      "戀愛\n",
      "相遇\n",
      "分離\n",
      "忘記\n",
      "心醉\n",
      "驀然\n",
      "吹過\n",
      "思念\n",
      "靈魂\n",
      "停止\n",
      "'''\n",
      "words = st.split('\\n')\n",
      "def poem():\n",
      "    n = randint(2, 7) # 決定有幾句\n",
      "\n",
      "    for i in range(n):\n",
      "        m = randint(2, 5) # 決定每句的長度\n",
      "        sentence = sample(words, m)\n",
      "        print(\" \".join(sentence))\n",
      "poem()\n"
     ]
    }
   ],
   "source": [
    "%save \"poem.py\" 62 59-60 66-67"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "於是, 在終端機中, 我們就可以與詩相遇...\n",
    "\n",
    "![在終端機中寫首詩](images/run_poem.png)"
   ]
  }
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