Python script to find distance between two zipcodes. May use Google or Bing APIs

distance_between_zipcodes.py

import urllib2
import csv
import json
import time

#Output file 
out_file = open('distance_output.csv','a')


i = 0
na_count = 0

with open('zip_to_geocode.csv', 'rt') as in_file:
    try:
        reader = csv.reader(in_file)
        writer = csv.writer(out_file, delimiter=',')
        
        #TODO
        api_key_bing = [Enter your bing api key here]
        api_key_google = [Enter your google api key here]

        for row in reader:
            i = i+1
            #print(" ".join(row))
            line = " ".join(row).split()
            order_id = line[0]
            zip1 = line[1].zfill(5)
            zip2 = line[2].zfill(5)
            
            #Use the suitable service. Comment the other
            
            #def_google_url = "http://maps.googleapis.com/maps/api/distancematrix/json?origins="+zip1+"&destinations="+zip2+"&mode=car&sensor=false&api_key="+api_key_google
            def_bing_url = "http://dev.virtualearth.net/REST/V1/Routes/Driving?wp.0="+ zip1 +"&wp.1="+zip2 + "&avoid=minimizeTolls&key=" + api_key_bing
            
            #The row from which geocoding has to start
            start_row = 1
            
            if(i<start_row):
              continue
            else:
              print order_id
            
            #Set the sleep time here to reduce the frequency of API call
            if(i%2 == 0):
              time.sleep(0.5)
            
            #Set a limit on NA values
            if(na_count > 4):
              print("Limits exceeded")
              break
            
            try:
                
                response = urllib2.urlopen(def_bing_url)
                data = json.load(response)
                
                #Enable the following lines if using Google webserive instead of Bing
                
                #dist = data['rows'][0]['elements'][0]['distance']['value']
                #dist = dist/1000.0
                #na_count = 0
                
                dist = data['resourceSets'][0]['resources'][0]['travelDistance']
                na_count = 0
            except:
                dist = "NA"
                na_count = na_count +1
            
            #Save into a file
            print str(dist)+","+str(i)+"\n"
            writer.writerow([order_id,zip1,zip2,str(dist)])
    finally:
        in_file.close()
        out_file.close()