Awesome
Google Maps API Polyline String Decoder
This repo contains a Python function that will convert encoded polyline strings (as returned by the Google Maps API) into a list of lat/lon pairs. If you have arcpy, you can pass the steps object (APIresponse['routes'][0]['legs'][0]['steps']
) to convert_to_shapefile() and it will create a polyline shapefile based on your route.
decode_polyline() is a direct port of Mapbox's JavaScript decode function which is in turn based on the official Google document.
Usage
To decode a polyline string into a list of lat/lon pairs, use decode_polyline():
decode_polyline('azljFjss{S?oA?kB')
>>> [(38.57329, -109.55078), (38.57329, -109.55038), (38.57329, -109.54984)]
To convert a Maps API response to a shapefile, use convert_to_shapefile():
# Get directions as JSON from the Maps API
APIresponse = get_google_directions('grand junction, co', 'moab, ut')
# Create shapefile based off the returned route
convert_to_shapefile(APIresponse['routes'][0]['legs'][0]['steps'], r"C:\routes\route.shp")
>>> 'C:\\routes\\route.shp'
It's pretty straightforward. I couldn't find an existing Python implementation when I looked so I decided to port one.