Chapter 1.ipynb

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  {
   "cell_type": "markdown",
   "id": "b24efce7",
   "metadata": {},
   "source": [
    "# French Deck"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "5b0db121",
   "metadata": {},
   "outputs": [],
   "source": [
    "import collections\n",
    "\n",
    "Card = collections.namedtuple('Card', ['rank', 'suit'])\n",
    "\n",
    "class FrenchDeck:\n",
    "    ranks = [str(n) for n in range(2, 11)] + list('JQKA')\n",
    "    suits = 'spades diamonds clubs hearts'.split()\n",
    "    \n",
    "    def __init__(self):\n",
    "        self._cards = [Card(rank, suit) for suit in self.suits\n",
    "                       for rank in self.ranks]\n",
    "    def __len__(self):\n",
    "        return len(self._cards)\n",
    "    \n",
    "    def __getitem__(self, position):\n",
    "        return self._cards[position]\n",
    "    "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "411ca011",
   "metadata": {},
   "source": [
    "The use of the `collections.namedtuple` is interesting as namedtuple can be used to build classes of objects that are just bundles of attributes with no custom methods, like a database record."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "id": "5e32893b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'schnouzer'"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "Dog = collections.namedtuple('Dog',['age','breed'])\n",
    "dogs = [Dog(10,'schnouzer'), Dog(5,'labrador'), Dog(3,'poodle')]\n",
    "dogs[0]"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "4e035aa0",
   "metadata": {},
   "source": [
    "Based on how we've constructed our deck, we can leverage other python code."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "id": "a66853d4",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "Card(rank='8', suit='diamonds')"
      ]
     },
     "execution_count": 44,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from random import choice\n",
    "deck = FrenchDeck()\n",
    "choice(deck)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "e4586032",
   "metadata": {},
   "source": [
    "Implementing the `__getitem__` method means that our class automatically supports slicing..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 48,
   "id": "c15de800",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[Card(rank='K', suit='hearts'), Card(rank='A', suit='hearts')]"
      ]
     },
     "execution_count": 48,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "deck[50:]"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3fec0514",
   "metadata": {},
   "source": [
    "and iteration."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "id": "e7b86607",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Card(rank='2', suit='spades')\n",
      "Card(rank='3', suit='spades')\n",
      "Card(rank='4', suit='spades')\n",
      "Card(rank='5', suit='spades')\n",
      "Card(rank='6', suit='spades')\n",
      "Card(rank='7', suit='spades')\n",
      "Card(rank='8', suit='spades')\n",
      "Card(rank='9', suit='spades')\n",
      "Card(rank='10', suit='spades')\n",
      "Card(rank='J', suit='spades')\n"
     ]
    }
   ],
   "source": [
    "for card in deck[:10]:\n",
    "    print(card)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ec08ab2e",
   "metadata": {},
   "source": [
    "We can also sort our deck."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 51,
   "id": "6dfacf7f",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Card(rank='2', suit='clubs')\n",
      "Card(rank='2', suit='diamonds')\n",
      "Card(rank='2', suit='hearts')\n",
      "Card(rank='2', suit='spades')\n",
      "Card(rank='3', suit='clubs')\n",
      "Card(rank='3', suit='diamonds')\n",
      "Card(rank='3', suit='hearts')\n",
      "Card(rank='3', suit='spades')\n",
      "Card(rank='4', suit='clubs')\n",
      "Card(rank='4', suit='diamonds')\n",
      "Card(rank='4', suit='hearts')\n",
      "Card(rank='4', suit='spades')\n",
      "Card(rank='5', suit='clubs')\n",
      "Card(rank='5', suit='diamonds')\n",
      "Card(rank='5', suit='hearts')\n",
      "Card(rank='5', suit='spades')\n",
      "Card(rank='6', suit='clubs')\n",
      "Card(rank='6', suit='diamonds')\n",
      "Card(rank='6', suit='hearts')\n",
      "Card(rank='6', suit='spades')\n",
      "Card(rank='7', suit='clubs')\n",
      "Card(rank='7', suit='diamonds')\n",
      "Card(rank='7', suit='hearts')\n",
      "Card(rank='7', suit='spades')\n",
      "Card(rank='8', suit='clubs')\n",
      "Card(rank='8', suit='diamonds')\n",
      "Card(rank='8', suit='hearts')\n",
      "Card(rank='8', suit='spades')\n",
      "Card(rank='9', suit='clubs')\n",
      "Card(rank='9', suit='diamonds')\n",
      "Card(rank='9', suit='hearts')\n",
      "Card(rank='9', suit='spades')\n",
      "Card(rank='10', suit='clubs')\n",
      "Card(rank='10', suit='diamonds')\n",
      "Card(rank='10', suit='hearts')\n",
      "Card(rank='10', suit='spades')\n",
      "Card(rank='J', suit='clubs')\n",
      "Card(rank='J', suit='diamonds')\n",
      "Card(rank='J', suit='hearts')\n",
      "Card(rank='J', suit='spades')\n",
      "Card(rank='Q', suit='clubs')\n",
      "Card(rank='Q', suit='diamonds')\n",
      "Card(rank='Q', suit='hearts')\n",
      "Card(rank='Q', suit='spades')\n",
      "Card(rank='K', suit='clubs')\n",
      "Card(rank='K', suit='diamonds')\n",
      "Card(rank='K', suit='hearts')\n",
      "Card(rank='K', suit='spades')\n",
      "Card(rank='A', suit='clubs')\n",
      "Card(rank='A', suit='diamonds')\n",
      "Card(rank='A', suit='hearts')\n",
      "Card(rank='A', suit='spades')\n"
     ]
    }
   ],
   "source": [
    "suit_values = dict(spades=3, hearts=2, diamonds=1, clubs=0)\n",
    "\n",
    "def spades_high(card):\n",
    "    rank_value = FrenchDeck.ranks.index(card.rank)\n",
    "    return rank_value * len(suit_values) + suit_values[card.suit]\n",
    "\n",
    "for card in sorted(deck,key=spades_high):\n",
    "    print(card)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "533f80b2",
   "metadata": {},
   "source": [
    "# Vector"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "id": "a85ba808",
   "metadata": {},
   "outputs": [],
   "source": [
    "from math import hypot\n",
    "\n",
    "class Vector:\n",
    "    def __init__(self, x=0, y=0):\n",
    "        self.x = x\n",
    "        self.y = y\n",
    "\n",
    "    def __repr__(self):\n",
    "        return 'Vector(%r, %r)' % (self.x, self.y)\n",
    "\n",
    "    def __abs__(self):\n",
    "        return hypot(self.x, self.y)\n",
    "    \n",
    "    def __bool__(self):\n",
    "        return bool(abs(self))\n",
    "\n",
    "    def __add__(self, other):\n",
    "        x = self.x + other.x\n",
    "        y = self.y + other.y\n",
    "        return Vector(x, y)\n",
    "\n",
    "    def __mul__(self, scalar):\n",
    "        return Vector(self.x * scalar, self.y * scalar)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "id": "530f9405",
   "metadata": {},
   "outputs": [
    {
     "ename": "TypeError",
     "evalue": "unsupported operand type(s) for *: 'int' and 'Vector'",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
      "Cell \u001b[1;32mIn [56], line 1\u001b[0m\n\u001b[1;32m----> 1\u001b[0m \u001b[38;5;241m2\u001b[39m\u001b[38;5;241m*\u001b[39mVector(\u001b[38;5;241m1\u001b[39m,\u001b[38;5;241m1\u001b[39m)\n",
      "\u001b[1;31mTypeError\u001b[0m: unsupported operand type(s) for *: 'int' and 'Vector'"
     ]
    }
   ],
   "source": [
    "Vector(1,1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "48c432ce",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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