schweizmobil-gpx.py

import gpxpy.gpx
import requests
import sys

ROUTE_TYPES = {
    'national': 'WanderlandRoutenNational',
    'regional': 'WanderlandRoutenRegional',
    'local': 'WanderlandRoutenLokal',
}

def lv03_to_wgs84(y, x):
    y_aux = (y - 600000)/1000000
    x_aux = (x - 200000)/1000000
    lng = (2.6779094
           + 4.728982 * y_aux
           + 0.791484 * y_aux * x_aux
           + 0.1306 * y_aux * x_aux ** 2
           - 0.0436 * y_aux ** 3) * 100/36
    lat = (16.9023892
           + 3.238272 * x_aux
           - 0.270978 * y_aux ** 2
           - 0.002528 * x_aux ** 2
           - 0.0447 * y_aux ** 2 * x_aux
           - 0.0140 * x_aux ** 3) * 100/36
    return lat, lng

def schweizmobil_url(route_type, route_nr):
    args = f'{ROUTE_TYPES[route_type]}={route_nr}'
    return f'https://map.schweizmobil.ch/api/4/query/featuresmultilayers?{args}'

def fetch_schweizmobil_points(route_type, route_nr):
    feature = requests.get(schweizmobil_url(route_type, route_nr)).json()
    return feature['features'][0]['geometry']['coordinates'][0]

def gpx_from_points(wgs84_points):
    segment = gpxpy.gpx.GPXTrackSegment()
    for (lat, lon) in wgs84_points:
        segment.points.append(gpxpy.gpx.GPXTrackPoint(lat, lon))

    track = gpxpy.gpx.GPXTrack()
    track.segments.append(segment)
    gpx = gpxpy.gpx.GPX()
    gpx.tracks.append(track)
    return gpx

if __name__ == '__main__':
    if len(sys.argv) not in (3, 4):
        print(f'usage: {sys.argv[0]} <national|regional|local> <route_nr> [out.gpx]',
              file=sys.stderr)
        sys.exit(1)

    route_type = sys.argv[1]
    if route_type not in ROUTE_TYPES:
        print(f'error: {route_type} is not {national, regional, local}',
              file=sys.stderr)
        sys.exit(1)

    try:
        route_nr = sys.argv[2]
    except ValueError:
        print(f'error: invalid route number {route_nr}', file=sys.stderr)
        sys.exit(1)

    lv03_points = fetch_schweizmobil_points(route_type, route_nr)
    wgs84_points = [lv03_to_wgs84(y, x) for (y, x) in lv03_points]
    gpx = gpx_from_points(wgs84_points)

    filename = sys.argv[3] if len(sys.argv) == 4 else 'out.gpx'
    open(filename, 'wb').write(gpx.to_xml().encode('utf-8'))

@delroth My hero, thank you for this script! I adapted it to work with Veloland:

ROUTE_TYPES = {
    'national': 'VelolandRoutenNational',
    'regional': 'VelolandRoutenRegional',
    'local': 'VelolandRoutenLokal',
}