Django (1.3) Google Maps v3 Geocoder service lookup example

helpers.py

import urllib, urllib2, simplejson
from django.utils.encoding import smart_str

def get_lat_lng(location):
    
    # http://djangosnippets.org/snippets/293/
    # http://code.google.com/p/gmaps-samples/source/browse/trunk/geocoder/python/SimpleParser.py?r=2476
    # http://stackoverflow.com/questions/2846321/best-and-simple-way-to-handle-json-in-django
    # http://djangosnippets.org/snippets/2399/
    
    location = urllib.quote_plus(smart_str(location))
    url = 'http://maps.googleapis.com/maps/api/geocode/json?address=%s&sensor=false' % location
    response = urllib2.urlopen(url).read() 
    result = simplejson.loads(response)
    if result['status'] == 'OK':
       lat = str(result['results'][0]['geometry']['location']['lat'])
       lng = str(result['results'][0]['geometry']['location']['lng'])
       return '%s,%s' % (lat, lng)
    else:
        return ''

models.py

# ...

from app.helpers import get_lat_lng

# ...

class Place(models.Model):
    
    title    = models.CharField(_(u'title'), max_length=255)
    address1 = models.CharField(_(u'address'), max_length=255, blank=True)
    address2 = models.CharField(_(u'address (cont.)'), max_length=255, blank=True)
    city     = models.CharField(_(u'city'), max_length=255, blank=True)
    state    = USStateField(_(u'state'), blank=True)
    zip      = models.CharField(_(u'ZIP'), max_length=10, blank=True)
    country  = models.CharField(_(u'country'), blank=True, max_length=100)
    latlng   = models.CharField(_(u'Latitude/Longitude'), blank=True, max_length=100, help_text=_(u'Note: This field will be filled-in automatically based on the other address bits.'))
    phone    = PhoneNumberField(_(u'phone'), blank=True)
    email    = models.EmailField(_(u'e-mail'), blank=True)
    website  = models.URLField(_(u'website'), blank=True)
    about    = models.TextField(_(u'about'), blank=True)
    
    class Meta:
        abstract = True
    
    def save(self, *args, **kwargs):
        # If latlng has no value:
        if not self.latlng:
            # Add + between fields with values:
            location = '+'.join(filter(None, (self.address1, self.address2, self.city, self.state, self.zip, self.country)))
            # Attempt to get latitude/longitude from Google Geocoder service v.3:
            self.latlng = get_lat_lng(location)
        super(Place, self).save(*args, **kwargs)

class Stadium(Place):
    
    slug = models.SlugField(_(u'slug'), max_length=255, unique=True)
    
    class Meta:
        pass
    
    @models.permalink
    def get_absolute_url(self):
        return('stadium_detail', (), { 'slug': self.slug })
    
    def __unicode__(self):
        return u'%s' % self.title

# ...