tps_vehiclepos-variables.py

#this script will query OpenData API to get the current positions for Sydney Trains. It will then use this information to plot the
#positions on a map

from google.transit import gtfs_realtime_pb2
import requests
import datetime
import boto3
import os
import time
from pytz import timezone
from decimal import Decimal

#list all variables --start

baseURL = 'https://api.transport.nsw.gov.au/v1/gtfs/vehiclepos/'   # Define URL for opendata API
headers = {'Authorization': 'apikey <insert your opendata api key here>'}   # Define header for opendata API
bucketName = os.environ['BUCKET']   # Set up bucket from environment variable
transportPositionTable = os.environ['TRANSPORTPOSITION_TABLE'] #dynamodb table for pushpin labels
bucketImagesKey = "images/" # set bucket key for images
HtmlLandingpagename = "vehiclelocation.html" #this is the landing html page that will load the image file to show the current position of vehicles

#Define operators for opendata API. Possible operators are ['sydneytrains', 'buses', 'ferries', 'lightrail', 'nswtrains', 'regionbuses', 'metro']
operators = ['sydneytrains']

#we will use bing maps to plot the locations
maps_bing_prefix = "https://dev.virtualearth.net/REST/v1/Imagery/Map/Road?mapsize=20000,20000&"
maps_bing_apikey = "format=jpeg&dcl=1&key=<insert your bing maps api key here>"
maps_error_imageURL = "https://image.shutterstock.com/image-photo/image-white-text-message-will-600w-1012395526.jpg" #show this image when there are errors
                                                                                                                     #generating map
maps_bing_pushpin_limit = 100 #this is the maximum pushpins that bing maps allows
inactive_vehicle_datetime_limit = 10 #(in minutes) this will be used to identify inactive vehicles. If a vehicle's
                                     #last stop id timestamp is at least inactive_vehicle_datetime_limit minutes old, 
                                     # then it is considered to be inactive
maps_active_vehicle_icon = '4'       #this is the icon that will be used to show active vehicles on the map
maps_inactive_vehicle_icon = '10'    #this is the icon that will be used to show inactive vehicles on the map

legend_vehicle_displayed_on_map_color = "#00bfff" #this color will be used to show legend entries for which the vehicle is displayed on map

lastpushpinLabel = 0      #this will be used to generate labels for pushpins. Each pushpin will have a number, which will be associated with a description.
                          #the association will be displayed under a legends section on the right hand side of the web page showing the map.
                          #the vehicle's label will be used as the description

#the dicts below allow generating labels for the pushpins that will be mapped. Each pushpin will have a label and a description.
dict_pushpinLabel_to_desc_map = {} #this dict will associate a pushpin label to its description.
dict_vehicleId_to_pushpinLabel_map = {} #this dict will associate a vehicleId to the pushpin label it has been associated to on the map.
pushpin_url = ""  #this is the url for the map with the pushpins containing the vehicle positions
total_vehicles_found = 0 #this is the total vehicles found, mapped or not

dynamodb_item_expiry_in_days = 2 #number of days after which items in dynamodb will be automatically deleted. Using DynamoDB TTL
tz_sydney = timezone('Australia/Sydney')  # Set up timezone
#list all variables --end

s3 = boto3.resource('s3')  # Define boto3 object to do s3 operations
dynamodb = boto3.resource('dynamodb') # Define boto3 object to do dynamodb operations
pushpinLabelsTable = dynamodb.Table(transportPositionTable)

# Initialize gtfs_realtime_pb2.FeedMessage
feed = gtfs_realtime_pb2.FeedMessage()