Uses Google Distance Matric API to get distances (in meters) between an airport and a list of lat/lon values. Writes to stdout.

apdm.py

#! /usr/bin/env python
# -*- coding: utf-8 -*-

import fileinput
from itertools import groupby
import json
from tablib import Dataset
import googlemaps
import begin


def chunks(data, chunk_size):
    """Generator that yields ``chunk_size`` long lists from ``data``, an
    iterable"""

    for _, item in groupby(enumerate(data), lambda k: k[0] // chunk_size):
        yield [x for _, x in item]


def dm_to_dist(out):
    """Generator extracting distances from result returned by Distance Matrix
    API"""

    for item in out['rows'][0]['elements']:
        try:
            dist = item['distance']['value']
        except KeyError:
            dist = item['status']

        yield dist


@begin.start(auto_convert=True, short_args=False)
def main(apikey:  """Google API key""",
         airport: """3 letter airport code""",
         keycol:  """heading label for key column in `infile`""",
         infile:  """tabular input data that includes key, lat and lon as
                  signed decimals""" = '-',
         latcol:  """heading label of latitude column in `infile`""" =
                  'latitude',
         loncol:  """heading label of longitude column in `infile`""" =
                  'longitude',
         reqsize: """number of lat/lon pairs to be submitted per request (max.
                  25)""" = 25,
         delay:   """optional delay in seconds between api requests""" = 0.0):
    """
    Uses Google Distance Matrix API to get distances (in meters) between an
    airport and a list of lat/lon values. Writes to stdout.
    """

    gmaps = googlemaps.Client(key=apikey)

    with fileinput.input((infile)) as fp:
        locations = Dataset(headers=next(fp).split())
        for line in fp:
            locations.append(line.split())

    keys = locations[keycol]
    latlons = ((float(lat), float(lon)) for lat, lon in
            zip(locations[latcol], locations[loncol]))

    print('{0}\t{1}'.format(keycol, airport))
    for key_chunk, ll_chunk in zip(chunks(keys, reqsize), chunks(latlons,
                                                                 reqsize)):
        out = gmaps.distance_matrix(['{0} airport'.format(airport)], ll_chunk,
               mode='driving', units='metric')
        for key, dist in zip(key_chunk, dm_to_dist(out)):
            print('{0}\t{1}'.format(key, dist))