def signal_distance(lat1,lng1,lat2,lng2):
    import simplejson, urllib
    orig_coord =lat1,lng1
    dest_coord = lat2,lng2
    #API request
    url = "https://maps.googleapis.com/maps/api/distancematrix/json?origins={0}&destinations={1}&mode=transit&language=zh-TW&key=AIzaSyBlwZDhGYNTrxXiQblz20v3poJTA7zTVho".format(str(orig_coord),str(dest_coord))

    result = simplejson.load(urllib.urlopen(url))
    print result
signal_distance(25.082969,121.5549714,24.9988582,121.5788795)