17.01.2012 - Google Weather Api

Google's weather API + Python + Django

Google offers weather data via XML feed. The can be accessed with the following URL:

http://www.google.com/ig/api?weather=[LOCATION]&hl=[LANGUAGE]

LOCATION: The LOCATION parameter defines the weather station. This can be a country together with a postal code (POSTAL CODE-COUNTRY) or the name of a city. The former method provides a more accurate result because there exit two or more cities with the same name.

LANGUAGE: The LANGUAGE parameter determinates the language of the provided XML feed. Valid values can be found here: http://code.google.com/intl/de-DE/apis/language/translate/v1/reference.html#LangNameArray

Let's get the actual weather and a weather forecast for the next days for Caleta de Fuste on Fuerteventura: The LOCATION and LANGUAGE parameters will be: '35610-Fuerteventura' and 'en'. Open the following link to get an XML feed with the actual weather information for Caleta de Fuste: http://www.google.com/ig/api?weather=35610-Fuerteventura&hl=en.

Here is an example for converting the feed into python dictionaries and lists:

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# vim: ai ts=4 sts=4 et sw=4
import xml.dom.minidom
import urllib
import urllib2

def weathertodict(xmlstring):
    doc = xml.dom.minidom.parseString(xmlstring)
    return elementtodict(doc.documentElement)

def elementtodict(parent):
    
    # get first child
    child = parent.firstChild
    
    if (not child):
        return None
    
    elif (child.hasAttribute('data')):
        
        # convert tags and data attributes to dictionary
        v = {}
        while child.nextSibling:
            v.update({child.tagName : child.getAttribute('data')})
            child = child.nextSibling
        return v
    
    d={}
    while child is not None:
        
        if (child.nodeType == xml.dom.minidom.Node.ELEMENT_NODE):
            
            # create or extend entry with tag name
            try:
                d[child.tagName]
            except KeyError:
                d[child.tagName]=[]
            
            # append node values, recursive call
            d[child.tagName].append(elementtodict(child))
        
        # select next sibling
        child = child.nextSibling
            
    return d

def main():
    request = 'http://www.google.com/ig/api?weather=%s&hl=%s' % ('35610-Fuerteventura', 'de')
    xml = unicode(urllib2.urlopen(urllib2.Request(request)).read(), 'ISO-8859-1').encode('utf-8')
    weather_dict = weathertodict(xml)
    weather = weather_dict.get('weather')[0]
    info = weather.get('forecast_information')[0]
    current = weather.get('current_conditions')[0]
    forecast = weather.get('forecast_conditions')
    print '#'*20
    print info
    print '#'*20
    print current
    print '#'*20
    print forecast
    
if __name__ == "__main__":
    main()

Django template tag

The aforementioned methods can be used in a django inclusion tag to show actual weather information for a specific location in a Django template:

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# vim: ai ts=4 sts=4 et sw=4

import urllib
import urllib2
from django import template
from google_weather.utils import weathertodict

register = template.Library()

@register.inclusion_tag('google_weather/weather_widget.html')
def google_weather(location, language):
    request = 'http://www.google.com/ig/api?weather=%s&hl=%s' % (location, language)
    xml = unicode(urllib2.urlopen(urllib2.Request(request)).read(), 'ISO-8859-1').encode('utf-8')
    weather_dict = weathertodict(xml).get('weather')[0]    
    return {
        'weather_dict' : weather_dict,
    }

An example for weather_widget.html could look like this:

<div class="forecast">
    
    <!-- forecast information -->
    <div class="forecast-information">
        <span class="city">{{ weather_dict.forecast_information.0.city }}</span>
    </div>
    
    <!-- current conditions -->
    <div class="current-conditions">
        <span class="icon"><img src="http://www.google.com/{{ weather_dict.current_conditions.0.icon }}" /></span>
        <span class="temp">{{ weather_dict.current_conditions.0.temp_c }} °C</span>
        <span class="condition">{{ weather_dict.current_conditions.0.condition }}</span>
        <span class="humidity">{{ weather_dict.current_conditions.0.humidity }}</span>
    </div>
    
    <!-- forecasts -->
    <div class="forecasts">
        {% for day in weather_dict.forecast_conditions %}
        <div class="forecast-day">
            <span class="icon"><img src="http://www.google.com/{{ day.icon }}" /></span>
            <span class="day">{{ day.day_of_week }}</span>
            <span class="high-low">{{ day.high }}°C / {{ day.low }}°C</span>
        </div>
        {% endfor %}
    </div>

</div>