                   geojson_data[column_name]['features'].push({
                                        "type": "Feature",
                                        "geometry": {'type': formatted_data[line_key][column_name + "." + 'type'],
                                                    'coordinates': formatted_data[line_key][column_name + "." + 'coordinates']},
                                        "properties": formatted_data[line_key]}) // contient des choses superflues, mais est-ce un problème ?
  