An SL4A (Android) Python script that polls the MetroDan station page and keeps track of ETAs for specific routes. The script notifies of ETA changes using Android's speech synthesis API.

metrodan-bus-tracker.py

###--# MetroDan Bus Tracker / Announcer 0.5.1a
# (c) 2013-2014 by IceDragon - All rights reserved
# 
# This script Polls MetroDan "real-time" bus website and keeps the user
# informed of the buses they are interested in via Speech To Text.
#
# This script is still work-in-progress.
#
# Author: IceDragon <icedragon at quickfox org>
#
# Changelog:
#	0.5.1a	- Indentation bugfix
#	0.5a	- Added conectivity issues handler that avoids crashes
#	0.4a	- Added "special mode" for old city station and route 8

import android

import urllib2
import re
import time
import sys

###--# Pseudo-Constants #--####################################################
RE_TIME_TABLE = re.compile("<tr><td>([0-9]+)</td><td>([^<]+)</td></tr>")

LOOKUP_URL_FORMAT = 'http://m.ontime3g.com/?stop=%d&company=md'

HEBREW_WORDS = {
    " \xd7\x93\xd7\xa7\xd7\x95\xd7\xaa": " mins",
    " \xd7\x93\xd7\xa7\xd7\x94": " min",
    " \xd7\x95": " and",
    " \xd7\xa9\xd7\xa2\xd7\x94": " hour"
}

TMP_STOP_IDS = {
   'Hapoalim': 11121,
   'Old City': 11126,
   'BGU Rear': 11214,
   'BGU AUX':  15332,
   'BGU Stop': 13949, 
   'BGU Soroka': 13518
}

BUS_ID_LIST = {
	# Default
	None:	[24, 34, 7, 8],
	# Old city - ignore other routes
	11126:	[8]
}


###--# Classes #--#############################################################
class Station:
    def __init__(self, station_id, name=None, filter=None):
        if not name:
            name = str(station_id)

        self.id = int(station_id)
        self.name = str(name)
        self.buses = {}
        self.last_scan = 0
        self.next_id = 0
        self.filter = filter

    def __str__(self):
        return self.name

    def __repr__(self):
        return "<Station #%d>" % self.id

    def getNextRoute(self):
        return int(self.next_id)

    def getEta(self, busNo):
        return self.buses[busNo]

    def getRouteList(self):
        return self.buses.keys()

    def getDataAge(self):
        return time.time() - self.last_scan

    def update(self):
        """Updates information about buses from the web"""
        url = LOOKUP_URL_FORMAT % self.id

        # Get the data as HTML from the website
        data = urllib2.urlopen(url).read()

        # Extract route information from the HTML data
        raw_routes = RE_TIME_TABLE.findall(data)
        routes = map(handleHebrewWords, raw_routes)

        # Process and store acquired information
        min = 9999
        for route in routes:
            (lineID, time_str) = route
            lineID = int(lineID)
            
            # Ignore uninteresting routes
            if self.filter and not self.filter.accept(lineID):
                continue
            
            eta_mins = translateTimeString(time_str)
            self.buses[lineID] = eta_mins
            
            if eta_mins > 0 and eta_mins < min:
                self.next_id = lineID
                min = eta_mins

        self.last_scan = time.time()
        return self


class BusFilter:
    def __init__(self, route_list = []):
        self.__routes = []
    
        for route_id in route_list:
            self.add(int(route_id))
    
    def __str__(self):
        return ", ".join(self.__routes)
    
    def accept(self, route_id):
        return route_id in self.__routes

    def add(self, id):
        self.__routes += [id]


###--# Standalone Helper Functions #--#########################################
def translateTimeString(timeString):
    last_num = -1
    hour_mult = 1
    hours = 1
    mins = 0

    for token in timeString.split(' '):
        if token.isdigit():
            last_num = int(token)

        elif token == "min":
            mins = 1

        elif token == "hour":
            if last_num > 0:
                hours = last_num
                last_num = -1

            hour_mult = 60

        elif token == "mins":
            mins = last_num
            last_num = -1

    return hours * hour_mult + mins


def handleHebrewWords(route):
    global HEBREW_WORDS
    (line, eta) = route

    for w in HEBREW_WORDS.keys():
        eta = eta.replace(w, HEBREW_WORDS[w])

    return (line, eta)


###--# Standalone Helper Functions #--#########################################
def say(msg):
    global DROID

    print msg
    DROID.ttsSpeak(msg)

def promptStationID():
    global TMP_STOP_IDS, DROID

    option_list = TMP_STOP_IDS.keys()
    
    DROID.dialogCreateAlert("Select Station")
    DROID.dialogSetSingleChoiceItems(option_list)
    DROID.dialogSetPositiveButtonText("Select")
    DROID.dialogShow()
    
    response  = DROID.dialogGetResponse()
    key_index = DROID.dialogGetSelectedItems().result[0]

    return TMP_STOP_IDS[ option_list[key_index] ]


def main(argv):
    global TMP_STOP_IDS, DROID, BUS_ID_LIST

    DROID = android.Android()
    
    station_id = promptStationID()

    DROID.wakeLockAcquirePartial()
	
    # If this station has a specific ID list, use that instead of the defaults
    id_set = None
    if station_id in BUS_ID_LIST:
        id_set = station_id

    if not id_set:
        mode_str = "standard"
    else:
        mode_str = "special"
	
    id_list = BUS_ID_LIST[id_set]

    say("Tracking established in %s mode" % mode_str)


    # Find the station and prepare for data fetching
    s = Station(station_id, "", BusFilter(id_list))
    while True:
		eta = 0
			
		try:
			s.update()
		except:
			say("Station update failed");
		else:
			if s.getRouteList() == []:
				say("Station tracking lost")
			else:
				next_id = s.getNextRoute()
				eta = s.getEta(next_id)
				say("Bus %d E T A: %d minutes" % (next_id, eta)) 

		sleep_time = 30
		if eta > 10:
			sleep_time = 120
		
		time.sleep(sleep_time)

    return 0


main([])