{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "54f244d8",
   "metadata": {},
   "source": [
    "# Retrieving data from Web Feature Service (WFS)\n",
    "\n",
    "Contents:\n",
    "- Introduce OGC WFS\n",
    "- Use OWSLib to get capabilities of WFS API\n",
    "- Retrieve data to geopandas"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "721a81ff",
   "metadata": {},
   "outputs": [],
   "source": [
    "import geopandas as gpd\n",
    "import requests\n",
    "import geojson\n",
    "from pyproj import CRS\n",
    "from owslib.wfs import WebFeatureService\n",
    "\n",
    "# Specify the url for the backend.\n",
    "# Here we are using data from Statistics Finland: https://www.stat.fi/org/avoindata/paikkatietoaineistot_en.html. (CC BY 4.0)\n",
    "url = \"http://geo.stat.fi/geoserver/tilastointialueet/wfs\"\n",
    "\n",
    "# Specify parameters (read data in json format).\n",
    "params = dict(\n",
    "    service=\"WFS\",\n",
    "    version=\"2.0.0\",\n",
    "    request=\"GetFeature\",\n",
    "    typeName=\"tilastointialueet:kunta4500k\",\n",
    "    outputFormat=\"json\",\n",
    ")\n",
    "\n",
    "# Fetch data from WFS using requests\n",
    "r = requests.get(url, params=params)\n",
    "\n",
    "# Create GeoDataFrame from geojson and set coordinate reference system\n",
    "data = gpd.GeoDataFrame.from_features(geojson.loads(r.content), crs=\"EPSG:3067\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "295d482e",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\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>geometry</th>\n",
       "      <th>kunta</th>\n",
       "      <th>vuosi</th>\n",
       "      <th>nimi</th>\n",
       "      <th>namn</th>\n",
       "      <th>name</th>\n",
       "      <th>bbox</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>POLYGON ((366787.924 7001300.583, 362458.797 6...</td>\n",
       "      <td>005</td>\n",
       "      <td>2022</td>\n",
       "      <td>Alajärvi</td>\n",
       "      <td>Alajärvi</td>\n",
       "      <td>Alajärvi</td>\n",
       "      <td>[321987.07200161, 6959704.55099558, 366787.924...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>POLYGON ((382543.364 7120022.976, 372645.944 7...</td>\n",
       "      <td>009</td>\n",
       "      <td>2022</td>\n",
       "      <td>Alavieska</td>\n",
       "      <td>Alavieska</td>\n",
       "      <td>Alavieska</td>\n",
       "      <td>[360962.99200022, 7104339.03799839, 382543.364...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>POLYGON ((343298.204 6961570.195, 345569.224 6...</td>\n",
       "      <td>010</td>\n",
       "      <td>2022</td>\n",
       "      <td>Alavus</td>\n",
       "      <td>Alavo</td>\n",
       "      <td>Alavus</td>\n",
       "      <td>[303353.32000378, 6922242.40698068, 345569.224...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>POLYGON ((436139.680 6798279.085, 435912.756 6...</td>\n",
       "      <td>016</td>\n",
       "      <td>2022</td>\n",
       "      <td>Asikkala</td>\n",
       "      <td>Asikkala</td>\n",
       "      <td>Asikkala</td>\n",
       "      <td>[403543.81899999, 6774122.31100019, 442401.762...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>POLYGON ((426631.036 6720528.076, 432565.266 6...</td>\n",
       "      <td>018</td>\n",
       "      <td>2022</td>\n",
       "      <td>Askola</td>\n",
       "      <td>Askola</td>\n",
       "      <td>Askola</td>\n",
       "      <td>[413073.96299999, 6704555.87800016, 435459.201...</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "                                            geometry kunta  vuosi       nimi  \\\n",
       "0  POLYGON ((366787.924 7001300.583, 362458.797 6...   005   2022   Alajärvi   \n",
       "1  POLYGON ((382543.364 7120022.976, 372645.944 7...   009   2022  Alavieska   \n",
       "2  POLYGON ((343298.204 6961570.195, 345569.224 6...   010   2022     Alavus   \n",
       "3  POLYGON ((436139.680 6798279.085, 435912.756 6...   016   2022   Asikkala   \n",
       "4  POLYGON ((426631.036 6720528.076, 432565.266 6...   018   2022     Askola   \n",
       "\n",
       "        namn       name                                               bbox  \n",
       "0   Alajärvi   Alajärvi  [321987.07200161, 6959704.55099558, 366787.924...  \n",
       "1  Alavieska  Alavieska  [360962.99200022, 7104339.03799839, 382543.364...  \n",
       "2      Alavo     Alavus  [303353.32000378, 6922242.40698068, 345569.224...  \n",
       "3   Asikkala   Asikkala  [403543.81899999, 6774122.31100019, 442401.762...  \n",
       "4     Askola     Askola  [413073.96299999, 6704555.87800016, 435459.201...  "
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "data.head()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "f2336f9b",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Prepare data for writing to various file formats\n",
    "data = data.drop(columns=[\"bbox\"])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "9a8d503d",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<Projected CRS: EPSG:3067>\n",
       "Name: ETRS89 / TM35FIN(E,N)\n",
       "Axis Info [cartesian]:\n",
       "- E[east]: Easting (metre)\n",
       "- N[north]: Northing (metre)\n",
       "Area of Use:\n",
       "- name: Finland - onshore and offshore.\n",
       "- bounds: (19.08, 58.84, 31.59, 70.09)\n",
       "Coordinate Operation:\n",
       "- name: TM35FIN\n",
       "- method: Transverse Mercator\n",
       "Datum: European Terrestrial Reference System 1989 ensemble\n",
       "- Ellipsoid: GRS 1980\n",
       "- Prime Meridian: Greenwich"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Check crs\n",
    "data.crs"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "e75296b5",
   "metadata": {},
   "outputs": [],
   "source": [
    "# filename\n",
    "layer_name = \"finland_municipalities.gpkg\"\n",
    "\n",
    "# Write data to disk\n",
    "# data.to_file(file_name, driver=\"GPKG\")"
   ]
  }
 ],
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