Django snippets: Google Geocode Lookup

#
# models.py
#
import urllib
import settings

def get_lat_long(location):
    key = settings.GOOGLE_API_KEY
    output = "csv"
    location = urllib.quote_plus(location)
    request = "http://maps.google.com/maps/geo?q=%s&output=%s&key=%s" % (location, output, key)
    data = urllib.urlopen(request).read()
    dlist = data.split(',')
    if dlist[0] == '200':
        return "%s, %s" % (dlist[2], dlist[3])
    else:
        return ''

Makes a call to Google's geocoder and returns the latitude and longitude as a string or returns an empty string. Called by the save method to save the lat and long to the db to be used when rendering maps on the frontend. Reduces the number of calls to geocoder by calling only when saving, not on every viewing of the object.

Be sure to import urllib and the project's settings, and to define GOOGLE_API_KEY in settings.py.

Example:

def save(self):
    location = "%s+%s+%s+%s" % (self.address, self.city, self.state, self.zip_code)
    self.lat_long = get_lat_long(location)
    if not self.lat_long:
        location = "%s+%s+%s" % (self.city, self.state, self.zip_code)
        self.lat_long = get_lat_long(location)

    super(Foo, self).save()

Author:: tonyskyday
Posted:: June 22, 2007
Language:: Python
Tags:: geocode google-api google-maps latitude longitude
Score:: 11 (after 11 ratings)

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Comments

falsh (on October 30, 2009):

get problems with : location = urllib.quote_plus(location)

when location has some accents

solution : location = smart_str(urllib.quote_plus(location))

anentropic (on November 22, 2009):

does this return "lat, lon" or "lon, lat" ?

P.S. great snippet, thanks

anentropic (on February 6, 2010):

@falsh ...you mean:

location = urllib.quote_plus(smart_str(location))

(the other way still throws errors if you have foreign chars)

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Google Geocode Lookup

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