Generate a earth grid and display them in a folium intercative HTML page

earth_grid.py

import folium
import s2geometry as s2
from folium.plugins import Draw


def get_grid_coords(min_lat, max_lat, min_lng, max_lng, level, max_cells=0):
    """Generate S2 cells covering a specified region at a given level."""
    region = s2.S2LatLngRect(
        s2.S2LatLng.FromDegrees(min_lat, min_lng),
        s2.S2LatLng.FromDegrees(max_lat, max_lng)
    )
    coverer = s2.S2RegionCoverer()
    coverer.set_min_level(level)
    coverer.set_max_level(level)
    if max_cells > 0:
        coverer.set_max_cells(max_cells)
    covering = coverer.GetCovering(region)
    grid_coords = []
    for cell_id in covering:
        cell = s2.S2Cell(cell_id)
        vertices = []
        for i in range(4):
            vertex = cell.GetVertex(i)
            latlng = s2.S2LatLng(vertex)
            vertices.append([latlng.lat().degrees(), latlng.lng().degrees()])
        # Close the polygon by adding the first point at the end
        vertices.append(vertices[0])
        grid_coords.append(vertices)
    return grid_coords


def display_map(polygons:list, output_filepath, center_lat, center_lon):
    """Save the polygons on a map on a html page with an Earth background."""
    m = folium.Map(location=[center_lat, center_lon], 
                zoom_start=3, 
                tiles='OpenStreetMap', 
                control_scale=True,
        )
    Draw(export=True).add_to(m)

    # Add S2 cells to the map
    for polygon in polygons:
        folium.Polygon(
            locations=polygon,
            color='blue',
            weight=1,
            fill=True,
            fill_opacity=0.2,
        ).add_to(m)
    m.save(output_filepath)

if __name__ == "__main__":
    # Define the region and level
    min_lat, max_lat = -50.0, 50.0   # https://www.coordonnees-gps.fr/
    min_lng, max_lng = -60, 60
    level = 5                       # http://s2geometry.io/resources/s2cell_statistics
    max_cells = 0                   #If 0 then no limit
    grid_coords = get_grid_coords(min_lat, max_lat, min_lng, max_lng, level, max_cells)

    
    # Define the region and level
    min_lat, max_lat = 45.0, 50.0   # https://www.coordonnees-gps.fr/
    min_lng, max_lng = 20, 40
    level = 6                       # http://s2geometry.io/resources/s2cell_statistics
    max_cells = 0                   #If 0 then no limit
    grid_coords2 = get_grid_coords(min_lat, max_lat, min_lng, max_lng, level, max_cells)
    
    grid_coords.extend(grid_coords2)

    center_lat = (min_lat + max_lat) / 2
    center_lng = (min_lng + max_lng) / 2

    display_map(grid_coords, 'test.html', center_lat, center_lng)