Dengue helper

dengue.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import urllib, urllib2, zipfile, StringIO, json, pprint, logging
import xml.etree.ElementTree as ET
from pykml import parser
import googlemaps
from math import radians, cos, sin, asin, sqrt


GOOGLE_GEO_KEY = ""
gmaps = googlemaps.Client(key=GOOGLE_GEO_KEY)

def haversine(lon1, lat1, lon2, lat2):
    """
    Calculate the great circle distance between two points 
    on the earth (specified in decimal degrees)
    """
    # convert decimal degrees to radians 
    lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])
    # haversine formula 
    dlon = lon2 - lon1 
    dlat = lat2 - lat1 
    a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
    c = 2 * asin(sqrt(a)) 
    km = 6367 * c
    return km

def simple_map(center_lat, center_lon, points):
  points_desc = "markers=color:blue|label:Y|%f,%f&markers=" % (center_lat, center_lon)
  for p in points:
    points_desc = points_desc + str(p.lat) + "," + str(p.lon) + "|"
  u = "https://maps.googleapis.com/maps/api/staticmap?center=%s,%s&scale=2&size=600x600&maptype=roadmap&key=%s&%s" % (center_lat, center_lon, GOOGLE_GEO_KEY, points_desc)
  # return urllib.quote(u, safe="://?&=")
  return u


def geo_lookup(query):
  geocode_result = gmaps.geocode(query, region='sg', components={"country":"SG"})
  if len(geocode_result) > 0:
    loc = geocode_result[0]['geometry']['location']
    lat, lon = loc['lat'], loc['lng']

    town = ''
    addr = geocode_result[0]['formatted_address']
    return True, lat, lon, addr
  return False, 0, 0, ''


def readDengue():
    url = 'https://data.gov.sg/api/action/package_metadata_show?id=dengue-cases'
    response = urllib2.urlopen(url)
    if response.code != 200:
        return None

    # Use the json module to load CKAN's response into a dictionary.
    response_dict = json.loads(response.read())

    # Check the contents of the response.
    if response_dict['success'] is not True:
        return None

    ret = []
    result = response_dict['result']
    title = result['name']
    last_updated = result['last_updated']
    identifier = result['identifier']
    kml_files = []
    for i in result['resources']:
          if i['format'] != 'KML':
                continue
          u = i['url']
          req = urllib2.Request(u, headers={'User-Agent': 'Hello World'})
          f = urllib2.urlopen(req)
          z = zipfile.ZipFile(StringIO.StringIO(f.read()))
          for name in z.namelist():
                a = z.open(name).read()
                root = parser.fromstring(a)
                folder = root.Document.Folder
                for p in folder.iterchildren():
                      if hasattr(p, 'MultiGeometry'):
                            co = p.MultiGeometry.Polygon.outerBoundaryIs.LinearRing.coordinates
                            co = [[float(j) for j in a.split(",")[:-1]] for a in str(co).strip().split(" ")][:-1]
                            
                            longitude, lat = 0,0
                            for c in co:
                                  longitude += c[0]
                                  lat += c[1]
                            longitude = longitude / len(co)
                            lat = lat / len(co)

                            ret.append((lat, longitude))

    return ret, last_updated