text: from itertools import chain
  
  from geopy.compat import urlencode
  from geopy.exc import GeocoderQueryError
  from geopy.geocoders.base import DEFAULT_SENTINEL, Geocoder
  from geopy.location import Location
  from geopy.util import logger
  from geopy.point import Point
  
  __all__ = ("Nominatim", )
  
  
  class Nominatim(Geocoder):
      """Nominatim geocoder for OpenStreetMap servers.
  
      Documentation at:
          https://wiki.openstreetmap.org/wiki/Nominatim
  
      .. attention::
         Nominatim requires each application to provide their own custom
         user-agent:
         ``geolocator = Nominatim(user_agent="my-application")``.
         Nominatim usage policy:
         https://operations.osmfoundation.org/policies/nominatim/
      """
  
      structured_query_params = {
          'street',
          'city',
          'county',
          'state',
          'country',
          'postalcode',
      }
  
      def __init__(
              self,
              format_string=None,
              view_box=None,
              bounded=False,
              country_bias=None,
              timeout=DEFAULT_SENTINEL,
              proxies=DEFAULT_SENTINEL,
              domain='nominatim.openstreetmap.org',
              scheme=None,
              user_agent=None,
              ssl_context=DEFAULT_SENTINEL,
              # Make sure to synchronize the changes of this signature in the
              # inheriting classes (e.g. PickPoint).
      ):
          """
          :param str format_string:
              See :attr:`geopy.geocoders.options.default_format_string`.
  
          :param tuple view_box: Coordinates to restrict search within.
              Accepts instances of the :class:`geopy.point.Point`
              ``[Point(22, 180), Point(-22, -180)]``,
              or iterables of numeric and string types ``[180, 22, -180, -22]``,
              ``["180", "22", "-180", "-22"]``
  
              .. versionchanged:: 1.15.0
                 Previously only a list of stringified coordinates was supported.
  
          :param str country_bias: Bias results to this country.
  
          :param bool bounded: Restrict the results to only items contained
              within the bounding view_box.
  
              .. versionadded:: 1.15.0
  
          :param int timeout:
              See :attr:`geopy.geocoders.options.default_timeout`.
  
          :param dict proxies:
              See :attr:`geopy.geocoders.options.default_proxies`.
  
          :param str domain: Should be the localized Openstreetmap domain to
              connect to. The default is ``'nominatim.openstreetmap.org'``,
              but you can change it to a domain of your own.
  
              .. versionadded:: 1.8.2
  
          :param str scheme:
              See :attr:`geopy.geocoders.options.default_scheme`.
  
              .. versionadded:: 1.8.2
  
          :param str user_agent:
              See :attr:`geopy.geocoders.options.default_user_agent`.
  
              .. versionadded:: 1.12.0
  
          :type ssl_context: :class:`ssl.SSLContext`
          :param ssl_context:
              See :attr:`geopy.geocoders.options.default_ssl_context`.
  
              .. versionadded:: 1.14.0
  
          """
          super(Nominatim, self).__init__(
              format_string=format_string,
              scheme=scheme,
              timeout=timeout,
              proxies=proxies,
              user_agent=user_agent,
              ssl_context=ssl_context,
          )
          self.country_bias = country_bias
          self.view_box = view_box
          self.bounded = bounded
          self.domain = domain.strip('/')
  
          self.api = "%s://%s/search" % (self.scheme, self.domain)
          self.reverse_api = "%s://%s/reverse" % (self.scheme, self.domain)
  
      def _construct_url(self, base_api, params):
          """
          Construct geocoding request url.
          The method can be overriden in Nominatim-based geocoders in order
          to extend URL parameters.
  
          :param string base_api: Geocoding function base address - self.api
              or self.reverse_api.
  
          :param dict params: Geocoding params.
  
          :return: string URL.
          """
          return "?".join((base_api, urlencode(params)))
  
      def geocode(
              self,
              query,
              exactly_one=True,
              timeout=DEFAULT_SENTINEL,
              limit=None,
              addressdetails=False,
              language=False,
              geometry=None
      ):
          """
          Return a location point by address.
  
          :param query: The address, query or a structured query
              you wish to geocode.
  
              .. versionchanged:: 1.0.0
                  For a structured query, provide a dictionary whose keys
                  are one of: `street`, `city`, `county`, `state`, `country`, or
                  `postalcode`. For more information, see Nominatim's
                  documentation for `structured requests`:
  
                      https://wiki.openstreetmap.org/wiki/Nominatim
  
          :type query: dict or str
  
          :param bool exactly_one: Return one result or a list of results, if
              available.
  
          :param int timeout: Time, in seconds, to wait for the geocoding service
              to respond before raising a :class:`geopy.exc.GeocoderTimedOut`
              exception. Set this only if you wish to override, on this call
              only, the value set during the geocoder's initialization.
  
          :param int limit: Maximum amount of results to return from Nominatim.
              Unless exactly_one is set to False, limit will always be 1.
  
              .. versionadded:: 1.13.0
  
          :param bool addressdetails: If you want in *Location.raw* to include
              addressdetails such as city_district, etc set it to True
  
          :param str language: Preferred language in which to return results.
              Either uses standard
              `RFC2616 <http://www.ietf.org/rfc/rfc2616.txt>`_
              accept-language string or a simple comma-separated
              list of language codes.
  
              .. versionadded:: 1.0.0
  
          :param str geometry: If present, specifies whether the geocoding
              service should return the result's geometry in `wkt`, `svg`,
              `kml`, or `geojson` formats. This is available via the
              `raw` attribute on the returned :class:`geopy.location.Location`
              object.
  
              .. versionadded:: 1.3.0
  
          :rtype: ``None``, :class:`geopy.location.Location` or a list of them, if
              ``exactly_one=False``.
  
          """
  
          if isinstance(query, dict):
              params = {
                  key: val
                  for key, val
                  in query.items()
                  if key in self.structured_query_params
              }
          else:
              params = {'q': self.format_string % query}
  
          params.update({
              'format': 'json'
          })
  
          if exactly_one:
              params['limit'] = 1
          elif limit:
              limit = int(limit)
              if limit < 1:
                  raise ValueError("Limit cannot be less than 1")
              params['limit'] = limit
  
          # `viewbox` apparently replaces `view_box`
          if self.view_box:
              if all(isinstance(point, Point) for point in self.view_box):
                  p1, p2 = self.view_box
                  params['viewbox'] = ','.join(str(p) for p in chain(p1[1::-1], p2[1::-1]))
              else:
                  params['viewbox'] = ','.join(str(coord) for coord in self.view_box)
  
          if self.bounded:
              params['bounded'] = 1
  
          if self.country_bias:
              params['countrycodes'] = self.country_bias
  
          if addressdetails:
              params['addressdetails'] = 1
  
          if language:
              params['accept-language'] = language
  
          if geometry is not None:
              geometry = geometry.lower()
              if geometry == 'wkt':
                  params['polygon_text'] = 1
              elif geometry == 'svg':
                  params['polygon_svg'] = 1
              elif geometry == 'kml':
                  params['polygon_kml'] = 1
              elif geometry == 'geojson':
                  params['polygon_geojson'] = 1
              else:
                  raise GeocoderQueryError(
                      "Invalid geometry format. Must be one of: "
                      "wkt, svg, kml, geojson."
                  )
  
          url = self._construct_url(self.api, params)
          logger.debug("%s.geocode: %s", self.__class__.__name__, url)
  
          return self._parse_json(
              self._call_geocoder(url, timeout=timeout), exactly_one
          )
  
      def reverse(
              self,
              query,
              exactly_one=True,
              timeout=DEFAULT_SENTINEL,
              language=False,
              addressdetails=True
      ):
          """
          Return an address by location point.
  
          :param query: The coordinates for which you wish to obtain the
              closest human-readable addresses.
          :type query: :class:`geopy.point.Point`, list or tuple of ``(latitude,
              longitude)``, or string as ``"%(latitude)s, %(longitude)s"``.
  
          :param bool exactly_one: Return one result or a list of results, if
              available.
  
          :param int timeout: Time, in seconds, to wait for the geocoding service
              to respond before raising a :class:`geopy.exc.GeocoderTimedOut`
              exception. Set this only if you wish to override, on this call
              only, the value set during the geocoder's initialization.
  
          :param str language: Preferred language in which to return results.
              Either uses standard
              `RFC2616 <http://www.ietf.org/rfc/rfc2616.txt>`_
              accept-language string or a simple comma-separated
              list of language codes.
  
              .. versionadded:: 1.0.0
  
          :param bool addressdetails: Whether or not to include address details,
              such as city, county, state, etc. in *Location.raw*
  
              .. versionadded:: 1.14.0
  
          :rtype: ``None``, :class:`geopy.location.Location` or a list of them, if
              ``exactly_one=False``.
  
          """
          try:
              lat, lon = [
                  x.strip() for x in
                  self._coerce_point_to_string(query).split(',')
              ]  # doh
          except ValueError:
              raise ValueError("Must be a coordinate pair or Point")
          params = {
              'lat': lat,
              'lon': lon,
              'format': 'json',
          }
          if language:
              params['accept-language'] = language
  
          params['addressdetails'] = 1 if addressdetails else 0
  
          url = self._construct_url(self.reverse_api, params)
          logger.debug("%s.reverse: %s", self.__class__.__name__, url)
  
          return self._parse_json(
              self._call_geocoder(url, timeout=timeout), exactly_one
          )
  
      @staticmethod
      def parse_code(place):
          # TODO make this a private API
          # Parse each resource.
          latitude = place.get('lat', None)
          longitude = place.get('lon', None)
          placename = place.get('display_name', None)
          if latitude and longitude:
              latitude = float(latitude)
              longitude = float(longitude)
          return Location(placename, (latitude, longitude), place)
  
      def _parse_json(self, places, exactly_one):
          if places is None:
              return None
          if not isinstance(places, list):
              places = [places]
          if not len(places):
              return None
          if exactly_one:
              return self.parse_code(places[0])
          else:
              return [self.parse_code(place) for place in places]
  