Geohash

Geohash is a Python module that provides functions for decoding and encoding Geohashes to and from latitude and longitude coordinates.

Example:

>>> import Geohash
>>> print 'Geohash for 42.6, -5.6:', Geohash.encode(42.6, -5.6)
Geohash for 42.6, -5.6: ezs42e44yx96

You can specify an arbitrary precision when encoding. The precision determines the number of characters in the Geohash:

>>> print 'Geohash for 42.6, -5.6:', Geohash.encode(42.6, -5.6, precision=5)
Geohash for 42.6, -5.6: ezs42

Decoding a Geohash returns a (latitude, longitude) tuple:

>>> print 'Coordinate for Geohash ezs42:', Geohash.decode('ezs42')
Coordinate for Geohash ezs42: ('42.6', '-5.6')

The Geohash module also provides exact decoding with error margin results. The decode_exactly function returns a tuple of four float values; latitude, longitude, latitude error margin, longitude error margin:

>>> print 'Exact coordinate for Geohash ezs42:\n', Geohash.decode_exactly('ezs42')
Exact coordinate for Geohash ezs42:
(42.60498046875, -5.60302734375, 0.02197265625, 0.02197265625)

The last two values are the plus/minus error margin of the latitude and longitude respectively. In this particular case the error margins happen to be the same for both the latitude and the longitude, but this is just a co-incidence due to the precision of the Geohash and thus the number of bits used for the latitude and longitude encoding, respectively.

Download

Geohash is available for download from github and from the Python Package Index.

License

Copyright (C) 2008 Leonard Norrgard <[email protected]> Copyright (C) 2015 Leonard Norrgard <[email protected]>

Geohash is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Geohash is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with Geohash. If not, see <http://www.gnu.org/licenses/>.

History

The Geohash encoding was originally described by Gustavo Niemeyer and the algorithm published in the Wikipedia Geohash article.

This implementation of Geohashes was written by Leonard Norrgard <[email protected]>.

Keywords

Geohash, GIS, latitude, longitude, encode, decode, Galileo, GPS, WGS84, coordinates, geotagging.