distances.py

import csv
import googlemaps
import os
import re
import time


gmaps = googlemaps.Client(key=os.getenv('GOOGLE_API_KEY'))

origins = ['559 Carpenter Ln, Philadelphia, PA 19119, USA']
destinations = []
rows = []

def write_rows_with_dist(write_head):
    matrix = gmaps.distance_matrix(origins, destinations, units='imperial')
    print(matrix)
    
    with open('pvpd7.csv', 'a') as newfile:
        fieldnames = ['VendorNo', 'VendorName', 'AddressLine1', 'AddressLine2',
            'City', 'State', 'ZipCode', 'TelephoneNo', 'Sort', 'Column1',
            'Purchases', 'GoogleAddress', 'Distance']
        writer=csv.DictWriter(newfile, fieldnames)
        if write_head:
            writer.writeheader()
        for row in rows:
            if 'destination_index' in row:
                row['GoogleAddress'] = matrix['destination_addresses'][row['destination_index']]
                if matrix['rows'][0]['elements'][row['destination_index']]['status'] == 'OK':
                    row['Distance'] = matrix['rows'][0]['elements'][row['destination_index']]['distance']['text']
                del row['destination_index']
            writer.writerow(row)

with open('pvpd6.csv', newline='') as csvfile:
    reader = csv.DictReader(csvfile)
    count = 0
    first_write = True
    for row in reader:
        if not row['GoogleAddress']:
            destination = row['VendorName']
            if not re.sub('[\W]+', '', row['AddressLine1']).lower().startswith('pobox'):
                destination = destination + ", " + row['AddressLine1']
            destinations.append(destination)
            row['destination_index'] = len(destinations) - 1
            count += 1
        rows.append(row)
        if count > 0 and count % 25 == 0:
            write_rows_with_dist(first_write)
            first_write = False
            rows = []
            destinations = []
            time.sleep(2)
    write_rows_with_dist(first_write)