text: # pip install geojson, ipyleaflet
  
  from geojson import Feature
  from geojson.geometry import MultiLineString
  from ipyleaflet import GeoJSON, Map
  
  def make_grid(step):
      return Feature(
          geometry=MultiLineString(
              coordinates=[[( lon, -90), (lon,  90)] for lon in range(-180, 180 + step, step)] + \
                          [[(-180, lat), (180, lat)] for lat in range( -90,  90 + step, step)] ))
  
  my_map = Map(zoom=1)
  my_map.add_layer(GeoJSON(data=make_grid(30)))
  