Item Based Collaborative Filtering.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This will be similar to User Based Collaborative Filtering."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "import pandas as pd\n",
    "import warnings\n",
    "from sklearn.metrics.pairwise import cosine_similarity\n",
    "warnings.filterwarnings('ignore')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Read the data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
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       "\n",
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       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>anime_id</th>\n",
       "      <th>name</th>\n",
       "      <th>genre</th>\n",
       "      <th>type</th>\n",
       "      <th>episodes</th>\n",
       "      <th>rating</th>\n",
       "      <th>members</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>5114</td>\n",
       "      <td>Fullmetal Alchemist: Brotherhood</td>\n",
       "      <td>Action, Adventure, Drama, Fantasy, Magic, Mili...</td>\n",
       "      <td>TV</td>\n",
       "      <td>64</td>\n",
       "      <td>9.26</td>\n",
       "      <td>793665</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>28977</td>\n",
       "      <td>Gintama°</td>\n",
       "      <td>Action, Comedy, Historical, Parody, Samurai, S...</td>\n",
       "      <td>TV</td>\n",
       "      <td>51</td>\n",
       "      <td>9.25</td>\n",
       "      <td>114262</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>9253</td>\n",
       "      <td>Steins;Gate</td>\n",
       "      <td>Sci-Fi, Thriller</td>\n",
       "      <td>TV</td>\n",
       "      <td>24</td>\n",
       "      <td>9.17</td>\n",
       "      <td>673572</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>9969</td>\n",
       "      <td>Gintama&amp;#039;</td>\n",
       "      <td>Action, Comedy, Historical, Parody, Samurai, S...</td>\n",
       "      <td>TV</td>\n",
       "      <td>51</td>\n",
       "      <td>9.16</td>\n",
       "      <td>151266</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   anime_id                              name  \\\n",
       "0     32281                    Kimi no Na wa.   \n",
       "1      5114  Fullmetal Alchemist: Brotherhood   \n",
       "2     28977                          Gintama°   \n",
       "3      9253                       Steins;Gate   \n",
       "4      9969                     Gintama&#039;   \n",
       "\n",
       "                                               genre   type episodes  rating  \\\n",
       "0               Drama, Romance, School, Supernatural  Movie        1    9.37   \n",
       "1  Action, Adventure, Drama, Fantasy, Magic, Mili...     TV       64    9.26   \n",
       "2  Action, Comedy, Historical, Parody, Samurai, S...     TV       51    9.25   \n",
       "3                                   Sci-Fi, Thriller     TV       24    9.17   \n",
       "4  Action, Comedy, Historical, Parody, Samurai, S...     TV       51    9.16   \n",
       "\n",
       "   members  \n",
       "0   200630  \n",
       "1   793665  \n",
       "2   114262  \n",
       "3   673572  \n",
       "4   151266  "
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "anime = pd.read_csv(\"anime.csv\")\n",
    "anime.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(12294, 7)\n",
      "(6135, 7)\n"
     ]
    }
   ],
   "source": [
    "# only select tv show and movie\n",
    "print(anime.shape)\n",
    "anime = anime[(anime['type'] == 'TV') | (anime['type'] == 'Movie')]\n",
    "print(anime.shape)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(1534, 7)"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# only select famous anime, 75% percentile\n",
    "m = anime['members'].quantile(0.75)\n",
    "anime = anime[(anime['members'] >= m)]\n",
    "anime.shape"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user_id</th>\n",
       "      <th>anime_id</th>\n",
       "      <th>rating</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>20</td>\n",
       "      <td>-1</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>1</td>\n",
       "      <td>24</td>\n",
       "      <td>-1</td>\n",
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       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>1</td>\n",
       "      <td>79</td>\n",
       "      <td>-1</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>1</td>\n",
       "      <td>226</td>\n",
       "      <td>-1</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>1</td>\n",
       "      <td>241</td>\n",
       "      <td>-1</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   user_id  anime_id  rating\n",
       "0        1        20      -1\n",
       "1        1        24      -1\n",
       "2        1        79      -1\n",
       "3        1       226      -1\n",
       "4        1       241      -1"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rating = pd.read_csv(\"rating.csv\")\n",
    "rating.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(7813737, 3)"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rating.shape"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# reduce the rows of rating, because my memory is not enough\n",
    "rating = rating[rating['user_id'] <= 10000]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(1042697, 3)"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rating.shape"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Replacing missing rating with NaN"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user_id</th>\n",
       "      <th>anime_id</th>\n",
       "      <th>rating</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
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       "      <th>1</th>\n",
       "      <td>1</td>\n",
       "      <td>24</td>\n",
       "      <td>NaN</td>\n",
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       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>1</td>\n",
       "      <td>79</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>1</td>\n",
       "      <td>226</td>\n",
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       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>1</td>\n",
       "      <td>241</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
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      ],
      "text/plain": [
       "   user_id  anime_id  rating\n",
       "0        1        20     NaN\n",
       "1        1        24     NaN\n",
       "2        1        79     NaN\n",
       "3        1       226     NaN\n",
       "4        1       241     NaN"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rating.loc[rating.rating == -1, 'rating'] = np.NaN\n",
    "rating.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Create index for anime name"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "name\n",
       "Kimi no Na wa.                      0\n",
       "Fullmetal Alchemist: Brotherhood    1\n",
       "Gintama°                            2\n",
       "Steins;Gate                         3\n",
       "Gintama&#039;                       4\n",
       "dtype: int64"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "anime_index = pd.Series(anime.index, index=anime.name)\n",
    "anime_index.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Join the data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>anime_id</th>\n",
       "      <th>name</th>\n",
       "      <th>genre</th>\n",
       "      <th>type</th>\n",
       "      <th>episodes</th>\n",
       "      <th>rating_x</th>\n",
       "      <th>members</th>\n",
       "      <th>user_id</th>\n",
       "      <th>rating_y</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "      <td>99</td>\n",
       "      <td>5.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "      <td>152</td>\n",
       "      <td>10.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "      <td>244</td>\n",
       "      <td>10.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "      <td>271</td>\n",
       "      <td>10.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>32281</td>\n",
       "      <td>Kimi no Na wa.</td>\n",
       "      <td>Drama, Romance, School, Supernatural</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>9.37</td>\n",
       "      <td>200630</td>\n",
       "      <td>278</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   anime_id            name                                 genre   type  \\\n",
       "0     32281  Kimi no Na wa.  Drama, Romance, School, Supernatural  Movie   \n",
       "1     32281  Kimi no Na wa.  Drama, Romance, School, Supernatural  Movie   \n",
       "2     32281  Kimi no Na wa.  Drama, Romance, School, Supernatural  Movie   \n",
       "3     32281  Kimi no Na wa.  Drama, Romance, School, Supernatural  Movie   \n",
       "4     32281  Kimi no Na wa.  Drama, Romance, School, Supernatural  Movie   \n",
       "\n",
       "  episodes  rating_x  members  user_id  rating_y  \n",
       "0        1      9.37   200630       99       5.0  \n",
       "1        1      9.37   200630      152      10.0  \n",
       "2        1      9.37   200630      244      10.0  \n",
       "3        1      9.37   200630      271      10.0  \n",
       "4        1      9.37   200630      278       NaN  "
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "joined = anime.merge(rating, how='inner', on='anime_id')\n",
    "joined.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Create a pivot table"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th>user_id</th>\n",
       "      <th>1</th>\n",
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       "      <th>9991</th>\n",
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       "      <th>9997</th>\n",
       "      <th>9998</th>\n",
       "      <th>9999</th>\n",
       "      <th>10000</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>name</th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
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       "      <th></th>\n",
       "      <th></th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>&amp;quot;Bungaku Shoujo&amp;quot; Movie</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
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       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Roots</th>\n",
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       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Sign</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>07-Ghost</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>6.0</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>5 rows × 9412 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "user_id                            1      2      3      5      7      8      \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "\n",
       "user_id                            9      10     11     12     ...    9991   \\\n",
       "name                                                           ...            \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN  ...      NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN  ...      NaN   \n",
       "\n",
       "user_id                            9992   9993   9994   9995   9996   9997   \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN    6.0   \n",
       "\n",
       "user_id                            9998   9999   10000  \n",
       "name                                                    \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN  \n",
       ".hack//Roots                         NaN    NaN    NaN  \n",
       ".hack//Sign                          NaN    NaN    NaN  \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN  \n",
       "07-Ghost                             NaN    NaN    NaN  \n",
       "\n",
       "[5 rows x 9412 columns]"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "joined = joined[['user_id', 'name', 'rating_y']]\n",
    "\n",
    "pivot = pd.pivot_table(joined, index='name', columns='user_id', values='rating_y')\n",
    "pivot.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(1490, 9412)"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pivot.shape"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Drop all users that never rate an anime"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "    <tr style=\"text-align: right;\">\n",
       "      <th>user_id</th>\n",
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       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
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       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
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       "    <tr>\n",
       "      <th>.hack//Sign</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
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       "    <tr>\n",
       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
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       "      <th>07-Ghost</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
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       "      <td>6.0</td>\n",
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       "      <td>NaN</td>\n",
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       "<p>5 rows × 9412 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "user_id                            1      2      3      5      7      8      \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "\n",
       "user_id                            9      10     11     12     ...    9991   \\\n",
       "name                                                           ...            \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN  ...      NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN  ...      NaN   \n",
       "\n",
       "user_id                            9992   9993   9994   9995   9996   9997   \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN    6.0   \n",
       "\n",
       "user_id                            9998   9999   10000  \n",
       "name                                                    \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN  \n",
       ".hack//Roots                         NaN    NaN    NaN  \n",
       ".hack//Sign                          NaN    NaN    NaN  \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN  \n",
       "07-Ghost                             NaN    NaN    NaN  \n",
       "\n",
       "[5 rows x 9412 columns]"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pivot.dropna(axis=1, how='all', inplace=True)\n",
    "pivot.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(1490, 9412)"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pivot.shape"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Center the mean around 0 (centered cosine / pearson)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "    <tr>\n",
       "      <th>.hack//Sign</th>\n",
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       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
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       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
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       "      <td>NaN</td>\n",
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       "    </tr>\n",
       "    <tr>\n",
       "      <th>07-Ghost</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>-1.598527</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>5 rows × 9412 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "user_id                            1      2      3      5      7      8      \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN    NaN   \n",
       "\n",
       "user_id                            9      10     11     12     ...    9991   \\\n",
       "name                                                           ...            \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN  ...      NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN  ...      NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN  ...      NaN   \n",
       "\n",
       "user_id                            9992   9993   9994   9995   9996   \\\n",
       "name                                                                   \n",
       "&quot;Bungaku Shoujo&quot; Movie     NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Roots                         NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Sign                          NaN    NaN    NaN    NaN    NaN   \n",
       ".hack//Tasogare no Udewa Densetsu    NaN    NaN    NaN    NaN    NaN   \n",
       "07-Ghost                             NaN    NaN    NaN    NaN    NaN   \n",
       "\n",
       "user_id                               9997   9998   9999   10000  \n",
       "name                                                              \n",
       "&quot;Bungaku Shoujo&quot; Movie        NaN    NaN    NaN    NaN  \n",
       ".hack//Roots                            NaN    NaN    NaN    NaN  \n",
       ".hack//Sign                             NaN    NaN    NaN    NaN  \n",
       ".hack//Tasogare no Udewa Densetsu       NaN    NaN    NaN    NaN  \n",
       "07-Ghost                          -1.598527    NaN    NaN    NaN  \n",
       "\n",
       "[5 rows x 9412 columns]"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pivot_norm = pivot.apply(lambda x: x - np.nanmean(x), axis=1)\n",
    "pivot_norm.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Item Based Collaborative Filtering"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style>\n",
       "    .dataframe thead tr:only-child th {\n",
       "        text-align: right;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: left;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th>user_id</th>\n",
       "      <th>1</th>\n",
       "      <th>2</th>\n",
       "      <th>3</th>\n",
       "      <th>5</th>\n",
       "      <th>7</th>\n",
       "      <th>8</th>\n",
       "      <th>9</th>\n",
       "      <th>10</th>\n",
       "      <th>11</th>\n",
       "      <th>12</th>\n",
       "      <th>...</th>\n",
       "      <th>9991</th>\n",
       "      <th>9992</th>\n",
       "      <th>9993</th>\n",
       "      <th>9994</th>\n",
       "      <th>9995</th>\n",
       "      <th>9996</th>\n",
       "      <th>9997</th>\n",
       "      <th>9998</th>\n",
       "      <th>9999</th>\n",
       "      <th>10000</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>name</th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>&amp;quot;Bungaku Shoujo&amp;quot; Movie</th>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>...</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Roots</th>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>...</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Sign</th>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>...</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>...</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>07-Ghost</th>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>...</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>-1.598527</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>5 rows × 9412 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "user_id                            1      2      3      5      7      8      \\\n",
       "name                                                                          \n",
       "&quot;Bungaku Shoujo&quot; Movie     0.0    0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Roots                         0.0    0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Sign                          0.0    0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Tasogare no Udewa Densetsu    0.0    0.0    0.0    0.0    0.0    0.0   \n",
       "07-Ghost                             0.0    0.0    0.0    0.0    0.0    0.0   \n",
       "\n",
       "user_id                            9      10     11     12     ...    9991   \\\n",
       "name                                                           ...            \n",
       "&quot;Bungaku Shoujo&quot; Movie     0.0    0.0    0.0    0.0  ...      0.0   \n",
       ".hack//Roots                         0.0    0.0    0.0    0.0  ...      0.0   \n",
       ".hack//Sign                          0.0    0.0    0.0    0.0  ...      0.0   \n",
       ".hack//Tasogare no Udewa Densetsu    0.0    0.0    0.0    0.0  ...      0.0   \n",
       "07-Ghost                             0.0    0.0    0.0    0.0  ...      0.0   \n",
       "\n",
       "user_id                            9992   9993   9994   9995   9996   \\\n",
       "name                                                                   \n",
       "&quot;Bungaku Shoujo&quot; Movie     0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Roots                         0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Sign                          0.0    0.0    0.0    0.0    0.0   \n",
       ".hack//Tasogare no Udewa Densetsu    0.0    0.0    0.0    0.0    0.0   \n",
       "07-Ghost                             0.0    0.0    0.0    0.0    0.0   \n",
       "\n",
       "user_id                               9997   9998   9999   10000  \n",
       "name                                                              \n",
       "&quot;Bungaku Shoujo&quot; Movie   0.000000    0.0    0.0    0.0  \n",
       ".hack//Roots                       0.000000    0.0    0.0    0.0  \n",
       ".hack//Sign                        0.000000    0.0    0.0    0.0  \n",
       ".hack//Tasogare no Udewa Densetsu  0.000000    0.0    0.0    0.0  \n",
       "07-Ghost                          -1.598527    0.0    0.0    0.0  \n",
       "\n",
       "[5 rows x 9412 columns]"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# fill NaN with 0\n",
    "pivot_norm.fillna(0, inplace=True)\n",
    "pivot_norm.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Calculate Similar Items"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style>\n",
       "    .dataframe thead tr:only-child th {\n",
       "        text-align: right;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: left;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th>name</th>\n",
       "      <th>&amp;quot;Bungaku Shoujo&amp;quot; Movie</th>\n",
       "      <th>.hack//Roots</th>\n",
       "      <th>.hack//Sign</th>\n",
       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
       "      <th>07-Ghost</th>\n",
       "      <th>11eyes</th>\n",
       "      <th>30-sai no Hoken Taiiku</th>\n",
       "      <th>91 Days</th>\n",
       "      <th>A-Channel</th>\n",
       "      <th>AKB0048</th>\n",
       "      <th>...</th>\n",
       "      <th>Zoku Natsume Yuujinchou</th>\n",
       "      <th>Zoku Sayonara Zetsubou Sensei</th>\n",
       "      <th>Zombie-Loan</th>\n",
       "      <th>Zutto Mae kara Suki deshita.: Kokuhaku Jikkou Iinkai</th>\n",
       "      <th>ef: A Tale of Melodies.</th>\n",
       "      <th>ef: A Tale of Memories.</th>\n",
       "      <th>s.CRY.ed</th>\n",
       "      <th>xxxHOLiC</th>\n",
       "      <th>xxxHOLiC Kei</th>\n",
       "      <th>xxxHOLiC Movie: Manatsu no Yoru no Yume</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>name</th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>&amp;quot;Bungaku Shoujo&amp;quot; Movie</th>\n",
       "      <td>1.000000</td>\n",
       "      <td>0.029269</td>\n",
       "      <td>0.021465</td>\n",
       "      <td>0.054258</td>\n",
       "      <td>0.029828</td>\n",
       "      <td>0.017774</td>\n",
       "      <td>-0.024699</td>\n",
       "      <td>-0.040539</td>\n",
       "      <td>0.032808</td>\n",
       "      <td>0.015381</td>\n",
       "      <td>...</td>\n",
       "      <td>0.022924</td>\n",
       "      <td>0.067584</td>\n",
       "      <td>0.029914</td>\n",
       "      <td>0.057437</td>\n",
       "      <td>0.092676</td>\n",
       "      <td>0.053568</td>\n",
       "      <td>-0.007820</td>\n",
       "      <td>0.028904</td>\n",
       "      <td>0.062385</td>\n",
       "      <td>0.030419</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Roots</th>\n",
       "      <td>0.029269</td>\n",
       "      <td>1.000000</td>\n",
       "      <td>0.278770</td>\n",
       "      <td>0.336105</td>\n",
       "      <td>0.099000</td>\n",
       "      <td>0.089652</td>\n",
       "      <td>0.015528</td>\n",
       "      <td>0.003461</td>\n",
       "      <td>0.068265</td>\n",
       "      <td>0.065131</td>\n",
       "      <td>...</td>\n",
       "      <td>0.011500</td>\n",
       "      <td>0.039758</td>\n",
       "      <td>0.072426</td>\n",
       "      <td>0.008782</td>\n",
       "      <td>0.049920</td>\n",
       "      <td>0.053877</td>\n",
       "      <td>0.045409</td>\n",
       "      <td>0.038875</td>\n",
       "      <td>0.066537</td>\n",
       "      <td>0.058233</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Sign</th>\n",
       "      <td>0.021465</td>\n",
       "      <td>0.278770</td>\n",
       "      <td>1.000000</td>\n",
       "      <td>0.304976</td>\n",
       "      <td>0.079774</td>\n",
       "      <td>0.044298</td>\n",
       "      <td>0.044370</td>\n",
       "      <td>0.005705</td>\n",
       "      <td>0.046192</td>\n",
       "      <td>0.015933</td>\n",
       "      <td>...</td>\n",
       "      <td>0.031619</td>\n",
       "      <td>0.045066</td>\n",
       "      <td>0.079867</td>\n",
       "      <td>0.015682</td>\n",
       "      <td>0.085431</td>\n",
       "      <td>0.055246</td>\n",
       "      <td>0.074836</td>\n",
       "      <td>0.064887</td>\n",
       "      <td>0.037908</td>\n",
       "      <td>0.064085</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>.hack//Tasogare no Udewa Densetsu</th>\n",
       "      <td>0.054258</td>\n",
       "      <td>0.336105</td>\n",
       "      <td>0.304976</td>\n",
       "      <td>1.000000</td>\n",
       "      <td>0.069433</td>\n",
       "      <td>0.063063</td>\n",
       "      <td>-0.008267</td>\n",
       "      <td>0.018654</td>\n",
       "      <td>0.058033</td>\n",
       "      <td>0.046196</td>\n",
       "      <td>...</td>\n",
       "      <td>0.036980</td>\n",
       "      <td>0.043281</td>\n",
       "      <td>0.091346</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.064953</td>\n",
       "      <td>0.039185</td>\n",
       "      <td>0.085909</td>\n",
       "      <td>0.021216</td>\n",
       "      <td>0.067155</td>\n",
       "      <td>0.060521</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>07-Ghost</th>\n",
       "      <td>0.029828</td>\n",
       "      <td>0.099000</td>\n",
       "      <td>0.079774</td>\n",
       "      <td>0.069433</td>\n",
       "      <td>1.000000</td>\n",
       "      <td>0.122958</td>\n",
       "      <td>0.034273</td>\n",
       "      <td>0.020435</td>\n",
       "      <td>0.066753</td>\n",
       "      <td>0.047780</td>\n",
       "      <td>...</td>\n",
       "      <td>0.047591</td>\n",
       "      <td>0.024697</td>\n",
       "      <td>0.118567</td>\n",
       "      <td>0.014620</td>\n",
       "      <td>0.046009</td>\n",
       "      <td>0.033981</td>\n",
       "      <td>0.074668</td>\n",
       "      <td>0.019609</td>\n",
       "      <td>0.033613</td>\n",
       "      <td>0.031543</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>5 rows × 1490 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "name                               &quot;Bungaku Shoujo&quot; Movie  \\\n",
       "name                                                                  \n",
       "&quot;Bungaku Shoujo&quot; Movie                           1.000000   \n",
       ".hack//Roots                                               0.029269   \n",
       ".hack//Sign                                                0.021465   \n",
       ".hack//Tasogare no Udewa Densetsu                          0.054258   \n",
       "07-Ghost                                                   0.029828   \n",
       "\n",
       "name                               .hack//Roots  .hack//Sign  \\\n",
       "name                                                           \n",
       "&quot;Bungaku Shoujo&quot; Movie       0.029269     0.021465   \n",
       ".hack//Roots                           1.000000     0.278770   \n",
       ".hack//Sign                            0.278770     1.000000   \n",
       ".hack//Tasogare no Udewa Densetsu      0.336105     0.304976   \n",
       "07-Ghost                               0.099000     0.079774   \n",
       "\n",
       "name                               .hack//Tasogare no Udewa Densetsu  \\\n",
       "name                                                                   \n",
       "&quot;Bungaku Shoujo&quot; Movie                            0.054258   \n",
       ".hack//Roots                                                0.336105   \n",
       ".hack//Sign                                                 0.304976   \n",
       ".hack//Tasogare no Udewa Densetsu                           1.000000   \n",
       "07-Ghost                                                    0.069433   \n",
       "\n",
       "name                               07-Ghost    11eyes  30-sai no Hoken Taiiku  \\\n",
       "name                                                                            \n",
       "&quot;Bungaku Shoujo&quot; Movie   0.029828  0.017774               -0.024699   \n",
       ".hack//Roots                       0.099000  0.089652                0.015528   \n",
       ".hack//Sign                        0.079774  0.044298                0.044370   \n",
       ".hack//Tasogare no Udewa Densetsu  0.069433  0.063063               -0.008267   \n",
       "07-Ghost                           1.000000  0.122958                0.034273   \n",
       "\n",
       "name                                91 Days  A-Channel   AKB0048  \\\n",
       "name                                                               \n",
       "&quot;Bungaku Shoujo&quot; Movie  -0.040539   0.032808  0.015381   \n",
       ".hack//Roots                       0.003461   0.068265  0.065131   \n",
       ".hack//Sign                        0.005705   0.046192  0.015933   \n",
       ".hack//Tasogare no Udewa Densetsu  0.018654   0.058033  0.046196   \n",
       "07-Ghost                           0.020435   0.066753  0.047780   \n",
       "\n",
       "name                                                ...                     \\\n",
       "name                                                ...                      \n",
       "&quot;Bungaku Shoujo&quot; Movie                    ...                      \n",
       ".hack//Roots                                        ...                      \n",
       ".hack//Sign                                         ...                      \n",
       ".hack//Tasogare no Udewa Densetsu                   ...                      \n",
       "07-Ghost                                            ...                      \n",
       "\n",
       "name                               Zoku Natsume Yuujinchou  \\\n",
       "name                                                         \n",
       "&quot;Bungaku Shoujo&quot; Movie                  0.022924   \n",
       ".hack//Roots                                      0.011500   \n",
       ".hack//Sign                                       0.031619   \n",
       ".hack//Tasogare no Udewa Densetsu                 0.036980   \n",
       "07-Ghost                                          0.047591   \n",
       "\n",
       "name                               Zoku Sayonara Zetsubou Sensei  Zombie-Loan  \\\n",
       "name                                                                            \n",
       "&quot;Bungaku Shoujo&quot; Movie                        0.067584     0.029914   \n",
       ".hack//Roots                                            0.039758     0.072426   \n",
       ".hack//Sign                                             0.045066     0.079867   \n",
       ".hack//Tasogare no Udewa Densetsu                       0.043281     0.091346   \n",
       "07-Ghost                                                0.024697     0.118567   \n",
       "\n",
       "name                               Zutto Mae kara Suki deshita.: Kokuhaku Jikkou Iinkai  \\\n",
       "name                                                                                      \n",
       "&quot;Bungaku Shoujo&quot; Movie                                            0.057437      \n",
       ".hack//Roots                                                                0.008782      \n",
       ".hack//Sign                                                                 0.015682      \n",
       ".hack//Tasogare no Udewa Densetsu                                           0.000000      \n",
       "07-Ghost                                                                    0.014620      \n",
       "\n",
       "name                               ef: A Tale of Melodies.  \\\n",
       "name                                                         \n",
       "&quot;Bungaku Shoujo&quot; Movie                  0.092676   \n",
       ".hack//Roots                                      0.049920   \n",
       ".hack//Sign                                       0.085431   \n",
       ".hack//Tasogare no Udewa Densetsu                 0.064953   \n",
       "07-Ghost                                          0.046009   \n",
       "\n",
       "name                               ef: A Tale of Memories.  s.CRY.ed  \\\n",
       "name                                                                   \n",
       "&quot;Bungaku Shoujo&quot; Movie                  0.053568 -0.007820   \n",
       ".hack//Roots                                      0.053877  0.045409   \n",
       ".hack//Sign                                       0.055246  0.074836   \n",
       ".hack//Tasogare no Udewa Densetsu                 0.039185  0.085909   \n",
       "07-Ghost                                          0.033981  0.074668   \n",
       "\n",
       "name                               xxxHOLiC  xxxHOLiC Kei  \\\n",
       "name                                                        \n",
       "&quot;Bungaku Shoujo&quot; Movie   0.028904      0.062385   \n",
       ".hack//Roots                       0.038875      0.066537   \n",
       ".hack//Sign                        0.064887      0.037908   \n",
       ".hack//Tasogare no Udewa Densetsu  0.021216      0.067155   \n",
       "07-Ghost                           0.019609      0.033613   \n",
       "\n",
       "name                               xxxHOLiC Movie: Manatsu no Yoru no Yume  \n",
       "name                                                                        \n",
       "&quot;Bungaku Shoujo&quot; Movie                                  0.030419  \n",
       ".hack//Roots                                                      0.058233  \n",
       ".hack//Sign                                                       0.064085  \n",
       ".hack//Tasogare no Udewa Densetsu                                 0.060521  \n",
       "07-Ghost                                                          0.031543  \n",
       "\n",
       "[5 rows x 1490 columns]"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# convert into dataframe to make it easier\n",
    "item_sim_df = pd.DataFrame(cosine_similarity(pivot_norm, pivot_norm), index=pivot_norm.index, columns=pivot_norm.index)\n",
    "item_sim_df.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "def get_similar_anime(anime_name):\n",
    "    if anime_name not in pivot_norm.index:\n",
    "        return None, None\n",
    "    else:\n",
    "        sim_animes = item_sim_df.sort_values(by=anime_name, ascending=False).index[1:]\n",
    "        sim_score = item_sim_df.sort_values(by=anime_name, ascending=False).loc[:, anime_name].tolist()[1:]\n",
    "        return sim_animes, sim_score"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Steins;Gate Movie: Fuka Ryouiki no Déjà vu with similarity of 0.25714456940512986\n",
      "Fullmetal Alchemist: Brotherhood with similarity of 0.18664806845268003\n",
      "Code Geass: Hangyaku no Lelouch R2 with similarity of 0.16413003201158918\n",
      "Suzumiya Haruhi no Shoushitsu with similarity of 0.16231289638293878\n",
      "Angel Beats! with similarity of 0.16095385954159877\n",
      "Tengen Toppa Gurren Lagann with similarity of 0.15634872712986464\n",
      "Fate/Zero 2nd Season with similarity of 0.15520331915668556\n",
      "Psycho-Pass with similarity of 0.15476024287681137\n",
      "Ano Hi Mita Hana no Namae wo Bokutachi wa Mada Shiranai. with similarity of 0.15111260584785854\n",
      "Fate/Zero with similarity of 0.15052446938924285\n"
     ]
    }
   ],
   "source": [
    "animes, score = get_similar_anime(\"Steins;Gate\")\n",
    "for x,y in zip(animes[:10], score[:10]):\n",
    "    print(\"{} with similarity of {}\".format(x, y))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Helper Function"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [],
   "source": [
    "# predict the rating of anime x by user y\n",
    "def predict_rating(user_id, anime_name, max_neighbor=10):\n",
    "    animes, scores = get_similar_anime(anime_name)\n",
    "    anime_arr = np.array([x for x in animes])\n",
    "    sim_arr = np.array([x for x in scores])\n",
    "    \n",
    "    # select only the anime that has already rated by user x\n",
    "    filtering = pivot_norm[user_id].loc[anime_arr] != 0\n",
    "    \n",
    "    # calculate the predicted score\n",
    "    s = np.dot(sim_arr[filtering][:max_neighbor], pivot[user_id].loc[anime_arr[filtering][:max_neighbor]]) \\\n",
    "            / np.sum(sim_arr[filtering][:max_neighbor])\n",
    "    \n",
    "    return s"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "8.4173726792034813"
      ]
     },
     "execution_count": 22,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "predict_rating(3, \"Steins;Gate\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "8.523652293486963"
      ]
     },
     "execution_count": 23,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "predict_rating(3, \"Cowboy Bebop\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Get Recommendation"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# recommend top n_anime for user x based on item collaborative filtering algorithm\n",
    "def get_recommendation(user_id, n_anime=10):\n",
    "    predicted_rating = np.array([])\n",
    "    \n",
    "    for _anime in pivot_norm.index:\n",
    "        predicted_rating = np.append(predicted_rating, predict_rating(user_id, _anime))\n",
    "    \n",
    "    # don't recommend something that user has already rated\n",
    "    temp = pd.DataFrame({'predicted':predicted_rating, 'name':pivot_norm.index})\n",
    "    filtering = (pivot_norm[user_id] == 0.0)\n",
    "    temp = temp.loc[filtering.values].sort_values(by='predicted', ascending=False)\n",
    "\n",
    "    # recommend n_anime anime\n",
    "    return anime.loc[anime_index.loc[temp.name[:n_anime]]]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style>\n",
       "    .dataframe thead tr:only-child th {\n",
       "        text-align: right;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: left;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>anime_id</th>\n",
       "      <th>name</th>\n",
       "      <th>genre</th>\n",
       "      <th>type</th>\n",
       "      <th>episodes</th>\n",
       "      <th>rating</th>\n",
       "      <th>members</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>53</th>\n",
       "      <td>6114</td>\n",
       "      <td>Rainbow: Nisha Rokubou no Shichinin</td>\n",
       "      <td>Drama, Historical, Seinen, Thriller</td>\n",
       "      <td>TV</td>\n",
       "      <td>26</td>\n",
       "      <td>8.64</td>\n",
       "      <td>139474</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>108</th>\n",
       "      <td>7655</td>\n",
       "      <td>Major S6</td>\n",
       "      <td>Comedy, Drama, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>25</td>\n",
       "      <td>8.49</td>\n",
       "      <td>24788</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>44</th>\n",
       "      <td>19647</td>\n",
       "      <td>Hajime no Ippo: Rising</td>\n",
       "      <td>Comedy, Drama, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>25</td>\n",
       "      <td>8.68</td>\n",
       "      <td>66756</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>32935</td>\n",
       "      <td>Haikyuu!!: Karasuno Koukou VS Shiratorizawa Ga...</td>\n",
       "      <td>Comedy, Drama, School, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>10</td>\n",
       "      <td>9.15</td>\n",
       "      <td>93351</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>254</th>\n",
       "      <td>18689</td>\n",
       "      <td>Diamond no Ace</td>\n",
       "      <td>Comedy, School, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>75</td>\n",
       "      <td>8.25</td>\n",
       "      <td>81384</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>475</th>\n",
       "      <td>28</td>\n",
       "      <td>Yakitate!! Japan</td>\n",
       "      <td>Comedy, Shounen</td>\n",
       "      <td>TV</td>\n",
       "      <td>69</td>\n",
       "      <td>8.05</td>\n",
       "      <td>50876</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>357</th>\n",
       "      <td>18179</td>\n",
       "      <td>Yowamushi Pedal</td>\n",
       "      <td>Comedy, Drama, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>38</td>\n",
       "      <td>8.16</td>\n",
       "      <td>91138</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>906</th>\n",
       "      <td>26</td>\n",
       "      <td>Texhnolyze</td>\n",
       "      <td>Action, Drama, Psychological, Sci-Fi</td>\n",
       "      <td>TV</td>\n",
       "      <td>22</td>\n",
       "      <td>7.78</td>\n",
       "      <td>95859</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>237</th>\n",
       "      <td>24277</td>\n",
       "      <td>Yowamushi Pedal: Grande Road</td>\n",
       "      <td>Comedy, Drama, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>24</td>\n",
       "      <td>8.28</td>\n",
       "      <td>50778</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>88</th>\n",
       "      <td>5941</td>\n",
       "      <td>Cross Game</td>\n",
       "      <td>Comedy, Drama, Romance, School, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>50</td>\n",
       "      <td>8.53</td>\n",
       "      <td>53108</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     anime_id                                               name  \\\n",
       "53       6114                Rainbow: Nisha Rokubou no Shichinin   \n",
       "108      7655                                           Major S6   \n",
       "44      19647                             Hajime no Ippo: Rising   \n",
       "5       32935  Haikyuu!!: Karasuno Koukou VS Shiratorizawa Ga...   \n",
       "254     18689                                     Diamond no Ace   \n",
       "475        28                                   Yakitate!! Japan   \n",
       "357     18179                                    Yowamushi Pedal   \n",
       "906        26                                         Texhnolyze   \n",
       "237     24277                       Yowamushi Pedal: Grande Road   \n",
       "88       5941                                         Cross Game   \n",
       "\n",
       "                                      genre type episodes  rating  members  \n",
       "53      Drama, Historical, Seinen, Thriller   TV       26    8.64   139474  \n",
       "108                   Comedy, Drama, Sports   TV       25    8.49    24788  \n",
       "44           Comedy, Drama, Shounen, Sports   TV       25    8.68    66756  \n",
       "5    Comedy, Drama, School, Shounen, Sports   TV       10    9.15    93351  \n",
       "254         Comedy, School, Shounen, Sports   TV       75    8.25    81384  \n",
       "475                         Comedy, Shounen   TV       69    8.05    50876  \n",
       "357          Comedy, Drama, Shounen, Sports   TV       38    8.16    91138  \n",
       "906    Action, Drama, Psychological, Sci-Fi   TV       22    7.78    95859  \n",
       "237          Comedy, Drama, Shounen, Sports   TV       24    8.28    50778  \n",
       "88   Comedy, Drama, Romance, School, Sports   TV       50    8.53    53108  "
      ]
     },
     "execution_count": 25,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "get_recommendation(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style>\n",
       "    .dataframe thead tr:only-child th {\n",
       "        text-align: right;\n",
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       "\n",
       "    .dataframe thead th {\n",
       "        text-align: left;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>anime_id</th>\n",
       "      <th>name</th>\n",
       "      <th>genre</th>\n",
       "      <th>type</th>\n",
       "      <th>episodes</th>\n",
       "      <th>rating</th>\n",
       "      <th>members</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>65</th>\n",
       "      <td>7472</td>\n",
       "      <td>Gintama Movie: Shinyaku Benizakura-hen</td>\n",
       "      <td>Action, Comedy, Historical, Parody, Samurai, S...</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>8.59</td>\n",
       "      <td>51185</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>28977</td>\n",
       "      <td>Gintama°</td>\n",
       "      <td>Action, Comedy, Historical, Parody, Samurai, S...</td>\n",
       "      <td>TV</td>\n",
       "      <td>51</td>\n",
       "      <td>9.25</td>\n",
       "      <td>114262</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>170</th>\n",
       "      <td>513</td>\n",
       "      <td>Tenkuu no Shiro Laputa</td>\n",
       "      <td>Adventure, Fantasy, Romance, Sci-Fi</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>8.38</td>\n",
       "      <td>151061</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>983</th>\n",
       "      <td>584</td>\n",
       "      <td>Noein: Mou Hitori no Kimi e</td>\n",
       "      <td>Adventure, Drama, Sci-Fi, Slice of Life</td>\n",
       "      <td>TV</td>\n",
       "      <td>24</td>\n",
       "      <td>7.74</td>\n",
       "      <td>56244</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>496</th>\n",
       "      <td>416</td>\n",
       "      <td>Kurenai no Buta</td>\n",
       "      <td>Action, Adventure, Comedy, Drama, Historical, ...</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>8.03</td>\n",
       "      <td>74028</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>148</th>\n",
       "      <td>558</td>\n",
       "      <td>Major S2</td>\n",
       "      <td>Comedy, Drama, Shounen, Sports</td>\n",
       "      <td>TV</td>\n",
       "      <td>26</td>\n",
       "      <td>8.41</td>\n",
       "      <td>30689</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>71</th>\n",
       "      <td>578</td>\n",
       "      <td>Hotaru no Haka</td>\n",
       "      <td>Drama, Historical</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>8.58</td>\n",
       "      <td>174878</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>834</th>\n",
       "      <td>2593</td>\n",
       "      <td>Kara no Kyoukai 1: Fukan Fuukei</td>\n",
       "      <td>Action, Mystery, Supernatural, Thriller</td>\n",
       "      <td>Movie</td>\n",
       "      <td>1</td>\n",
       "      <td>7.81</td>\n",
       "      <td>178880</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>46</th>\n",
       "      <td>10379</td>\n",
       "      <td>Natsume Yuujinchou San</td>\n",
       "      <td>Drama, Fantasy, Shoujo, Slice of Life, Superna...</td>\n",
       "      <td>TV</td>\n",
       "      <td>13</td>\n",
       "      <td>8.67</td>\n",
       "      <td>102322</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>11061</td>\n",
       "      <td>Hunter x Hunter (2011)</td>\n",
       "      <td>Action, Adventure, Shounen, Super Power</td>\n",
       "      <td>TV</td>\n",
       "      <td>148</td>\n",
       "      <td>9.13</td>\n",
       "      <td>425855</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     anime_id                                    name  \\\n",
       "65       7472  Gintama Movie: Shinyaku Benizakura-hen   \n",
       "2       28977                                Gintama°   \n",
       "170       513                  Tenkuu no Shiro Laputa   \n",
       "983       584             Noein: Mou Hitori no Kimi e   \n",
       "496       416                         Kurenai no Buta   \n",
       "148       558                                Major S2   \n",
       "71        578                          Hotaru no Haka   \n",
       "834      2593         Kara no Kyoukai 1: Fukan Fuukei   \n",
       "46      10379                  Natsume Yuujinchou San   \n",
       "6       11061                  Hunter x Hunter (2011)   \n",
       "\n",
       "                                                 genre   type episodes  \\\n",
       "65   Action, Comedy, Historical, Parody, Samurai, S...  Movie        1   \n",
       "2    Action, Comedy, Historical, Parody, Samurai, S...     TV       51   \n",
       "170                Adventure, Fantasy, Romance, Sci-Fi  Movie        1   \n",
       "983            Adventure, Drama, Sci-Fi, Slice of Life     TV       24   \n",
       "496  Action, Adventure, Comedy, Drama, Historical, ...  Movie        1   \n",
       "148                     Comedy, Drama, Shounen, Sports     TV       26   \n",
       "71                                   Drama, Historical  Movie        1   \n",
       "834            Action, Mystery, Supernatural, Thriller  Movie        1   \n",
       "46   Drama, Fantasy, Shoujo, Slice of Life, Superna...     TV       13   \n",
       "6              Action, Adventure, Shounen, Super Power     TV      148   \n",
       "\n",
       "     rating  members  \n",
       "65     8.59    51185  \n",
       "2      9.25   114262  \n",
       "170    8.38   151061  \n",
       "983    7.74    56244  \n",
       "496    8.03    74028  \n",
       "148    8.41    30689  \n",
       "71     8.58   174878  \n",
       "834    7.81   178880  \n",
       "46     8.67   102322  \n",
       "6      9.13   425855  "
      ]
     },
     "execution_count": 26,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "get_recommendation(5)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Compared to the user based collaborative filtering, the recommendation given is different. As we know, in the user based, so many user did not rate the anime. In the item based however, I think it is more robust because there is no anime that never rated by users."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
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