AKON Data Overview.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# AKON Metadata - Data Overview"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "*Get a first impression of the postcard metadata*"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Setup"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Using the [Pandas Python Data Analysis Library](https://pandas.pydata.org/).\n",
    "\n",
    "For an intro to pandas feel free to take a look at this [Workshop for CBioVikings](https://github.com/dblyon/PandasIntro) by David Lyon."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Load Data"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "`df` stands for *Data Frame*"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "df = pd.read_csv('akon_postcards_public_domain.csv.bz2')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## View Data"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Rough Overview"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "How much datasets are in there?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "28882"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(df)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "What does a dataset look like?\n",
    "Show me the first one!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Unnamed: 0</th>\n",
       "      <th>akon_id</th>\n",
       "      <th>id</th>\n",
       "      <th>altitude</th>\n",
       "      <th>building</th>\n",
       "      <th>city</th>\n",
       "      <th>color</th>\n",
       "      <th>comment</th>\n",
       "      <th>mountain</th>\n",
       "      <th>other</th>\n",
       "      <th>...</th>\n",
       "      <th>date</th>\n",
       "      <th>feature_class</th>\n",
       "      <th>feature_code</th>\n",
       "      <th>geoname_id</th>\n",
       "      <th>latitude</th>\n",
       "      <th>longitude</th>\n",
       "      <th>name</th>\n",
       "      <th>country_id</th>\n",
       "      <th>admin_name_1</th>\n",
       "      <th>admin_code_1</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>0</td>\n",
       "      <td>AK111_024</td>\n",
       "      <td>74685</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Kierling</td>\n",
       "      <td>True</td>\n",
       "      <td>1908</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>gelaufen 1908</td>\n",
       "      <td>P</td>\n",
       "      <td>PPL</td>\n",
       "      <td>2774449.0</td>\n",
       "      <td>48.30997</td>\n",
       "      <td>16.27616</td>\n",
       "      <td>Kierling</td>\n",
       "      <td>AT</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>1 rows × 29 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "   Unnamed: 0    akon_id     id  altitude building      city  color comment  \\\n",
       "0           0  AK111_024  74685       NaN      NaN  Kierling   True    1908   \n",
       "\n",
       "  mountain other     ...                date feature_class feature_code  \\\n",
       "0      NaN   NaN     ...       gelaufen 1908             P          PPL   \n",
       "\n",
       "  geoname_id  latitude  longitude      name country_id admin_name_1  \\\n",
       "0  2774449.0  48.30997   16.27616  Kierling         AT          NaN   \n",
       "\n",
       "  admin_code_1  \n",
       "0          NaN  \n",
       "\n",
       "[1 rows x 29 columns]"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.head(1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "There seem to be a few columns missing from the output. Let's fix that by setting pandas output options:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "pd.set_option('display.max_columns', 100)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Let's try again:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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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>Unnamed: 0</th>\n",
       "      <th>akon_id</th>\n",
       "      <th>id</th>\n",
       "      <th>altitude</th>\n",
       "      <th>building</th>\n",
       "      <th>city</th>\n",
       "      <th>color</th>\n",
       "      <th>comment</th>\n",
       "      <th>mountain</th>\n",
       "      <th>other</th>\n",
       "      <th>photographer</th>\n",
       "      <th>publisher</th>\n",
       "      <th>publisher_place</th>\n",
       "      <th>region</th>\n",
       "      <th>water_body</th>\n",
       "      <th>year</th>\n",
       "      <th>inventory_number</th>\n",
       "      <th>signature</th>\n",
       "      <th>revision_date</th>\n",
       "      <th>date</th>\n",
       "      <th>feature_class</th>\n",
       "      <th>feature_code</th>\n",
       "      <th>geoname_id</th>\n",
       "      <th>latitude</th>\n",
       "      <th>longitude</th>\n",
       "      <th>name</th>\n",
       "      <th>country_id</th>\n",
       "      <th>admin_name_1</th>\n",
       "      <th>admin_code_1</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>0</td>\n",
       "      <td>AK111_024</td>\n",
       "      <td>74685</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Kierling</td>\n",
       "      <td>True</td>\n",
       "      <td>1908</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>Geogr. Topogr. Bilder-Samml. 1944, 6380</td>\n",
       "      <td>2014-09-05 10:13:12.536</td>\n",
       "      <td>gelaufen 1908</td>\n",
       "      <td>P</td>\n",
       "      <td>PPL</td>\n",
       "      <td>2774449.0</td>\n",
       "      <td>48.30997</td>\n",
       "      <td>16.27616</td>\n",
       "      <td>Kierling</td>\n",
       "      <td>AT</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   Unnamed: 0    akon_id     id  altitude building      city  color comment  \\\n",
       "0           0  AK111_024  74685       NaN      NaN  Kierling   True    1908   \n",
       "\n",
       "  mountain other photographer publisher publisher_place region water_body  \\\n",
       "0      NaN   NaN          NaN       NaN             NaN    NaN        NaN   \n",
       "\n",
       "   year inventory_number                                signature  \\\n",
       "0   NaN              NaN  Geogr. Topogr. Bilder-Samml. 1944, 6380   \n",
       "\n",
       "             revision_date           date feature_class feature_code  \\\n",
       "0  2014-09-05 10:13:12.536  gelaufen 1908             P          PPL   \n",
       "\n",
       "   geoname_id  latitude  longitude      name country_id admin_name_1  \\\n",
       "0   2774449.0  48.30997   16.27616  Kierling         AT          NaN   \n",
       "\n",
       "  admin_code_1  \n",
       "0          NaN  "
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.head(1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Now we see all columns."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "What are all the columns called again?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "Index(['Unnamed: 0', 'akon_id', 'id', 'altitude', 'building', 'city', 'color',\n",
       "       'comment', 'mountain', 'other', 'photographer', 'publisher',\n",
       "       'publisher_place', 'region', 'water_body', 'year', 'inventory_number',\n",
       "       'signature', 'revision_date', 'date', 'feature_class', 'feature_code',\n",
       "       'geoname_id', 'latitude', 'longitude', 'name', 'country_id',\n",
       "       'admin_name_1', 'admin_code_1'],\n",
       "      dtype='object')"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.columns"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Show Random Entries"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Show me 3 random entries:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Unnamed: 0</th>\n",
       "      <th>akon_id</th>\n",
       "      <th>id</th>\n",
       "      <th>altitude</th>\n",
       "      <th>building</th>\n",
       "      <th>city</th>\n",
       "      <th>color</th>\n",
       "      <th>comment</th>\n",
       "      <th>mountain</th>\n",
       "      <th>other</th>\n",
       "      <th>photographer</th>\n",
       "      <th>publisher</th>\n",
       "      <th>publisher_place</th>\n",
       "      <th>region</th>\n",
       "      <th>water_body</th>\n",
       "      <th>year</th>\n",
       "      <th>inventory_number</th>\n",
       "      <th>signature</th>\n",
       "      <th>revision_date</th>\n",
       "      <th>date</th>\n",
       "      <th>feature_class</th>\n",
       "      <th>feature_code</th>\n",
       "      <th>geoname_id</th>\n",
       "      <th>latitude</th>\n",
       "      <th>longitude</th>\n",
       "      <th>name</th>\n",
       "      <th>country_id</th>\n",
       "      <th>admin_name_1</th>\n",
       "      <th>admin_code_1</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>458</th>\n",
       "      <td>458</td>\n",
       "      <td>AK114_189</td>\n",
       "      <td>76614</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Airolo</td>\n",
       "      <td>True</td>\n",
       "      <td>1909 gel</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>Geogr. Topogr. Bilder-Samml. 1944, 27</td>\n",
       "      <td>2014-09-09 08:50:37.905</td>\n",
       "      <td>gelaufen 1909</td>\n",
       "      <td>P</td>\n",
       "      <td>PPL</td>\n",
       "      <td>2661830.0</td>\n",
       "      <td>46.52847</td>\n",
       "      <td>8.60881</td>\n",
       "      <td>Airolo</td>\n",
       "      <td>CH</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>24510</th>\n",
       "      <td>24510</td>\n",
       "      <td>AK075_467</td>\n",
       "      <td>46922</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Klausen</td>\n",
       "      <td>False</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>1913.0</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>2014-08-21 10:05:32.779</td>\n",
       "      <td>1913</td>\n",
       "      <td>P</td>\n",
       "      <td>PPLA3</td>\n",
       "      <td>3178764.0</td>\n",
       "      <td>46.64001</td>\n",
       "      <td>11.56573</td>\n",
       "      <td>Klausen</td>\n",
       "      <td>IT</td>\n",
       "      <td>Südtirol</td>\n",
       "      <td>17</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>18564</th>\n",
       "      <td>18564</td>\n",
       "      <td>AK082_546</td>\n",
       "      <td>51980</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Velsen</td>\n",
       "      <td>False</td>\n",
       "      <td>v 1905</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",
       "      <td>2014-08-25 17:46:23.417</td>\n",
       "      <td>vor 1905</td>\n",
       "      <td>P</td>\n",
       "      <td>PPL</td>\n",
       "      <td>2745673.0</td>\n",
       "      <td>52.46000</td>\n",
       "      <td>4.65000</td>\n",
       "      <td>Velsen</td>\n",
       "      <td>NL</td>\n",
       "      <td>Nord-Holland</td>\n",
       "      <td>07</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       Unnamed: 0    akon_id     id  altitude building     city  color  \\\n",
       "458           458  AK114_189  76614       NaN      NaN   Airolo   True   \n",
       "24510       24510  AK075_467  46922       NaN      NaN  Klausen  False   \n",
       "18564       18564  AK082_546  51980       NaN      NaN   Velsen  False   \n",
       "\n",
       "        comment mountain other photographer publisher publisher_place region  \\\n",
       "458    1909 gel      NaN   NaN          NaN       NaN             NaN    NaN   \n",
       "24510       NaN      NaN   NaN          NaN       NaN             NaN    NaN   \n",
       "18564    v 1905      NaN   NaN          NaN       NaN             NaN    NaN   \n",
       "\n",
       "      water_body    year inventory_number  \\\n",
       "458          NaN     NaN              NaN   \n",
       "24510        NaN  1913.0              NaN   \n",
       "18564        NaN     NaN              NaN   \n",
       "\n",
       "                                   signature            revision_date  \\\n",
       "458    Geogr. Topogr. Bilder-Samml. 1944, 27  2014-09-09 08:50:37.905   \n",
       "24510                                    NaN  2014-08-21 10:05:32.779   \n",
       "18564                                    NaN  2014-08-25 17:46:23.417   \n",
       "\n",
       "                date feature_class feature_code  geoname_id  latitude  \\\n",
       "458    gelaufen 1909             P          PPL   2661830.0  46.52847   \n",
       "24510           1913             P        PPLA3   3178764.0  46.64001   \n",
       "18564       vor 1905             P          PPL   2745673.0  52.46000   \n",
       "\n",
       "       longitude     name country_id  admin_name_1 admin_code_1  \n",
       "458      8.60881   Airolo         CH           NaN          NaN  \n",
       "24510   11.56573  Klausen         IT      Südtirol           17  \n",
       "18564    4.65000   Velsen         NL  Nord-Holland           07  "
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.sample(3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Calling `sample` again yields different entries:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>Unnamed: 0</th>\n",
       "      <th>akon_id</th>\n",
       "      <th>id</th>\n",
       "      <th>altitude</th>\n",
       "      <th>building</th>\n",
       "      <th>city</th>\n",
       "      <th>color</th>\n",
       "      <th>comment</th>\n",
       "      <th>mountain</th>\n",
       "      <th>other</th>\n",
       "      <th>photographer</th>\n",
       "      <th>publisher</th>\n",
       "      <th>publisher_place</th>\n",
       "      <th>region</th>\n",
       "      <th>water_body</th>\n",
       "      <th>year</th>\n",
       "      <th>inventory_number</th>\n",
       "      <th>signature</th>\n",
       "      <th>revision_date</th>\n",
       "      <th>date</th>\n",
       "      <th>feature_class</th>\n",
       "      <th>feature_code</th>\n",
       "      <th>geoname_id</th>\n",
       "      <th>latitude</th>\n",
       "      <th>longitude</th>\n",
       "      <th>name</th>\n",
       "      <th>country_id</th>\n",
       "      <th>admin_name_1</th>\n",
       "      <th>admin_code_1</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>27658</th>\n",
       "      <td>27658</td>\n",
       "      <td>AK097_351</td>\n",
       "      <td>62277</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Station Brenner</td>\n",
       "      <td>Steinach am Brenner</td>\n",
       "      <td>False</td>\n",
       "      <td>1905 gel</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",
       "      <td>2014-09-02 11:15:45.988</td>\n",
       "      <td>vor 1905</td>\n",
       "      <td>P</td>\n",
       "      <td>PPLA3</td>\n",
       "      <td>2764557.0</td>\n",
       "      <td>47.08333</td>\n",
       "      <td>11.46667</td>\n",
       "      <td>Steinach am Brenner</td>\n",
       "      <td>AT</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14993</th>\n",
       "      <td>14993</td>\n",
       "      <td>AK021_515</td>\n",
       "      <td>12604</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Gross-Pöchlarn, Klein-Pöchlarn</td>\n",
       "      <td>False</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Ledermann</td>\n",
       "      <td>Wien</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>1917.0</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>2014-08-04 07:59:10.136</td>\n",
       "      <td>1917</td>\n",
       "      <td>P</td>\n",
       "      <td>PPLA3</td>\n",
       "      <td>2768627.0</td>\n",
       "      <td>48.20000</td>\n",
       "      <td>15.20000</td>\n",
       "      <td>Pöchlarn</td>\n",
       "      <td>AT</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15934</th>\n",
       "      <td>15934</td>\n",
       "      <td>AK025_596</td>\n",
       "      <td>15102</td>\n",
       "      <td>NaN</td>\n",
       "      <td>Pfarrkirche</td>\n",
       "      <td>Mondsee</td>\n",
       "      <td>False</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>1914.0</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>2014-08-04 07:59:10.187</td>\n",
       "      <td>1914</td>\n",
       "      <td>P</td>\n",
       "      <td>PPLA3</td>\n",
       "      <td>2771277.0</td>\n",
       "      <td>47.85648</td>\n",
       "      <td>13.34908</td>\n",
       "      <td>Mondsee</td>\n",
       "      <td>AT</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       Unnamed: 0    akon_id     id  altitude         building  \\\n",
       "27658       27658  AK097_351  62277       NaN  Station Brenner   \n",
       "14993       14993  AK021_515  12604       NaN              NaN   \n",
       "15934       15934  AK025_596  15102       NaN      Pfarrkirche   \n",
       "\n",
       "                                 city  color   comment mountain other  \\\n",
       "27658             Steinach am Brenner  False  1905 gel      NaN   NaN   \n",
       "14993  Gross-Pöchlarn, Klein-Pöchlarn  False       NaN      NaN   NaN   \n",
       "15934                         Mondsee  False       NaN      NaN   NaN   \n",
       "\n",
       "      photographer  publisher publisher_place region water_body    year  \\\n",
       "27658          NaN        NaN             NaN    NaN        NaN     NaN   \n",
       "14993          NaN  Ledermann            Wien    NaN        NaN  1917.0   \n",
       "15934          NaN        NaN             NaN    NaN        NaN  1914.0   \n",
       "\n",
       "      inventory_number signature            revision_date      date  \\\n",
       "27658              NaN       NaN  2014-09-02 11:15:45.988  vor 1905   \n",
       "14993              NaN       NaN  2014-08-04 07:59:10.136      1917   \n",
       "15934              NaN       NaN  2014-08-04 07:59:10.187      1914   \n",
       "\n",
       "      feature_class feature_code  geoname_id  latitude  longitude  \\\n",
       "27658             P        PPLA3   2764557.0  47.08333   11.46667   \n",
       "14993             P        PPLA3   2768627.0  48.20000   15.20000   \n",
       "15934             P        PPLA3   2771277.0  47.85648   13.34908   \n",
       "\n",
       "                      name country_id admin_name_1 admin_code_1  \n",
       "27658  Steinach am Brenner         AT          NaN          NaN  \n",
       "14993             Pöchlarn         AT          NaN          NaN  \n",
       "15934              Mondsee         AT          NaN          NaN  "
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.sample(3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Count Things"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "How many entries show things in Italy?\n",
    "\n",
    "Let's use the `country_id` for this question:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [],
   "source": [
    "df_in_italy = df[df['country_id'] == 'IT']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "2983"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(df_in_italy)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "How many postcards are in color?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [],
   "source": [
    "df_in_color = df[df['color'] == True]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "7075"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(df_in_color)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Can I do this in one line?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "7075"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(df[df['color'] == True])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "How many different publisher places are in the data set?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1324"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(df['publisher_place'].unique())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Show me some!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "ename": "AttributeError",
     "evalue": "'numpy.ndarray' object has no attribute 'sample'",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mAttributeError\u001b[0m                            Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-21-3d3e9c7ad7b5>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mdf\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m'publisher_place'\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0munique\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0msample\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m10\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;31mAttributeError\u001b[0m: 'numpy.ndarray' object has no attribute 'sample'"
     ]
    }
   ],
   "source": [
    "df['publisher_place'].unique().sample(10)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Oh, that doesn't work. Let's wrap it in a pandas DataFrame, step by step:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [],
   "source": [
    "publisher_places = df['publisher_place'].unique()"
   ]