pbp_com/apps/almanac/utils/wu_forecaster.py

"""
forecaster.py

This script is designed to run at a regular interval, polling various feeds from the National Weather Service and updating Django models WeatherCondition, WeatherAlert, and WeatherForecast in the Almanac application.

WeatherUnderground RSS Structure:

   feed
    entries
       0 - current weather conditions
         summary_detail
	   value - String of Temp, Hum, Pres, Cond, WindDir, WindSpd, CondImg

"""
from datetime import datetime, timedelta
from dateutil.parser import *
import urllib
import feedparser
import elementtree.ElementTree as ET
import time 

from almanac.models import WeatherConditions, WeatherAlert, WeatherForecast
from directory.models import Town

ALERT_ZONES={"Coastal_Hancock_County":'MEZ029',}
LOCATIONS={'04624':'Blue Hill',
           '04627':'Stonington',}


weather_url='http://rss.wunderground.com/auto/rss_full/ME/%s.xml?units=english'
alerts_url='http://www.weather.gov/alerts-beta/wwaatmget.php?x=%s'

def coords_for_zipcode(zipcode, client):
	coords=ET.fromstring(client.service.LatLonListZipCode(zipcode))
	coords=coords[0].text.split(',')
	return coords

def update_conditions():
	"""
		function process_conditions
			input: ElementTree object of weather conditions
			result: Look up new weather condition and save it to the db
	"""
	for location in LOCATIONS:
		feed=feedparser.parse(weather_url % location)
		args={}
		args['observation_time']=parse(feed.feed.updated, ignoretz=True)
		args['town']=Town.objects.get(name=LOCATIONS.get(location))  
		# First, we update the current conditions, assuming we have an update
		try:
			WeatherConditions.objects.get(observation_time__exact=args['observation_time'], town__exact=args['town'])
			print "Passing condition updates for %s..." % args['town']
			pass
		except:
			print "Going ahead with condition updates for %s..." % args['town']
			feed_cond=feed.entries[0].summary.split(" |")
			try: 
			    args['temperature']=float(feed_cond[0].split(": ")[1][0:4]) 
			except:
			    args['temperature']=float(feed_cond[0].split(": ")[1][0:3]) 
			args['humidity']=feed_cond[1].split(": ")[1]			
			args['pressure']=feed_cond[2].split(": ")[1].replace('        ', '')
			args['conditions']=feed_cond[3].split(": ")[1]
			args['wind_dir']=feed_cond[4].split(": ")[1]
			args['wind_speed']=float(feed_cond[5].split(": ")[1].split("mph")[0])
			condition=WeatherConditions.objects.create(**args)
			condition.save()
		# Now we try to get forecast updates which are everything after the current conditions: 
		for entry in feed.entries[1:]:	
			forecast_data=entry.summary.split(" - ")
			args={}
			args['observation_time']=parse(feed.feed.updated, ignoretz=True)
			print LOCATIONS.get(location)
			args['town']=Town.objects.get(name=LOCATIONS.get(location))  
			args['period']=forecast_data[0]
			try:
				WeatherForecast.objects.get(observation_time__exact=args['observation_time'], period=args['period'], town__exact=args['town'])
				print "Passing forecast update for %s..." % args['town']
				pass
			except:
				print "Going ahead with forecasts for %s" % args['town']
				try:
					args['conditions'] = forecast_data[1]
					forecast=WeatherForecast.objects.create(**args)
					forecast.save()
				except:
					print "Oops, no forecast data"
					pass


update_conditions()

def process_alerts(alerts, zone):
	root=alerts.getroot()
	if root[6][3].text.strip(" ").strip("\n   ")=="There are no active watches, warnings or advisories":
		pass
	else: # We have a alert, so lets process
		updated=parse(root[6][1].text)
		zone_id=ALERT_ZONES[zone]
		zone=zone.replace("_", " ")
		summary=root[6][5].text.strip("\n")
		effective=parse(root[6][6].text)
		expires=parse(root[6][7].text)
		status=root[6][8].text.strip("\n")
		msg_type=root[6][9].text.strip("\n")
		urgency=root[6][11].text.strip("\n")
		severity=root[6][12].text.strip("\n")
		certainty=root[6][13].text.strip("\n")
		area=root[6][14].text.strip("\n")
		try:
			WeatherAlert.objects.get(summary__exact=summary)
			pass
		except:
			alert=WeatherAlert.objects.create(updated=updated,
											  zone_id=zone_id,
											  zone=zone,
											  summary=summary,
											  effective=effective,
											  expires=expires,
											  status=status,
											  msg_type=msg_type,
											  urgency=urgency,
											  severity=severity,
											  certainty=certainty,
											  area=area)
			alert.save()
		

# Add alerts for given state
#for zone in ALERT_ZONES:
#    alerts=ET.parse(urllib.urlopen(alerts_url % ALERT_ZONES[zone]))
#    process_alerts(alerts, zone)


# Update current forecasts
'''for loc in LOCATIONS:
	now=datetime.now()
	nowString=datetime.strftime(now,"%Y-%m-%dT%H:%M")
	laterString=datetime.strftime(now + timedelta(days=7),"%Y-%m-%dT%H:%M")
	coords=coords_for_zipcode(LOCATIONS[loc], NOAA)
	forecast=ET.parse(NOAA.service.NDFDgen(coords[0], coords[1], 
		'time-series', nowString, laterString,					
		(1,1,1,1,1,1,1,1,1,1,1,1)))
	print forecast[0]'''
					




	
#url = f_url % (lat, lon)
#doc = ET.fromstring(urllib.urlopen(url))
#forecasts=[]
#for node in dom.getElementsByTagNameNS