pyqgis-easter-eggs-layers.py

import os

# Look at https://github.com/qgis/QGIS/blob/2d1aa68f0d044f2aced7ebeca8d2fa6b754ac970/src/app/qgsstatusbarcoordinateswidget.cpp#L113
# and https://github.com/qgis/QGIS/tree/master/resources/data
iface.newProject()

data_base_path = [QgsApplication.pkgDataPath(), 'resources', 'data']

world_map_path = os.path.join(*data_base_path, 'world_map.gpkg')
layers_world_map = ['countries', 'states_provinces', 'disputed_borders']

QgsProject.instance().addMapLayers([
    QgsVectorLayer(
        f"{world_map_path}|layername={layer}",
        layer.replace('_', ' ').capitalize(),
        "ogr"
    ) for layer in layers_world_map
])

json_layers = ['contributors.json', 'qgis-hackfests.json', 'user_groups_data.json']


qgis_vector_layers = []
for layer in json_layers:
    options = QgsVectorLayer.LayerOptions()
    options.loadDefaultStyle = False # To avoid using default qml associated style
    options.transformContext = QgsProject.instance().transformContext()
    qgis_vector_layers.append(
        QgsVectorLayer(
            os.path.join(*data_base_path, layer),
            layer.replace('_', ' ').replace('-', ' ').capitalize(),
            "ogr",
            options
        )
    )

QgsProject.instance().addMapLayers(qgis_vector_layers)


iface.mapCanvas().setProperty("retro", True)
iface.mapCanvas().refresh()