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Retrieve Latitude & Longitude for an Address from Google Geocoder V3

Author:
whardeman
Posted:
October 25, 2010
Language:
Python
Version:
1.2
Score:
-1 (after 1 ratings)

Very simple python class for querying Google Geocoder. Accepts a human-readable address, parses JSON results and sets lat and lng. (Full JSON results are stored to results property of GoogleLatLng for access to other attributes.)

This could easily be expanded to include the XML output option, etc.

Requires PycURL and simplejson.

Example:

>>> location = "1600 Amphitheatre Parkway, Mountain View, CA 94043"
>>> glatlng = GoogleLatLng()
>>> glatlng.requestLatLngJSON(location)
>>> print "Latitude: %s, Longitude: %s" % (glatlng.lat, glatlng.lng)
Latitude: 37.422782, Longitude: -122.085099`

Do not forget the usage limits, which include request rate throttling, otherwise, Google might ban you.

===

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import sys
import pycurl, urllib
import simplejson as json

class GoogleLatLng:
    """
    Send an address to Google Geocoder API and get JSON output back.
    Parse to retrieve latitude and longitude.
    There is a 24-hour usage limit, currently this is 2500 requests 
    but this could change in the future. Check Google's Terms of Use
    before employing this technique.
    """
    def __init__(self):
        self.lat = ""
        self.lng = ""
        self.results = ""

    def parseResults(self, buff):
        self.results = json.loads(buff)
        try:
                self.lat = self.results['results'][0]['geometry']['location']['lat']
                self.lng = self.results['results'][0]['geometry']['location']['lng']
        except:
                print >> sys.stderr, "An error occurred.\nQuery results: %s" % self.results

    def requestLatLngJSON(self, location):
        location = urllib.quote_plus(location)
        c = pycurl.Curl()
        c.setopt(c.URL, 'http://maps.googleapis.com/maps/api/geocode/json?sensor=false&address=%s' % location)
        c.setopt(c.WRITEFUNCTION, self.parseResults)
        c.perform()
        c.close()

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Comments

pjwalmsley (on April 14, 2014):

For those getting the following error:

(23, 'Failed writing body (0 != 1044)') pycurl

The callback function ParseResults must return. You can return "None" to resolve the error.

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