Python Notebook that steps through a process for creating a geojson file, from lat/long coordinate data that maps to polygons. The script maps each polygon to its corresponding ID so that the converted topojson file can be used as a map_layer, tied to the proper ID dimension, in Looker.
More info on Looker's custom map layers: https://help.looker.com/hc/en-us/articles/360001288168-Creating-Custom-Map-Regions