Import and export several files - QGIS

qgis-add-layers.py

"""
Add several CSV files as Delimited Text Layer(s) with x coordinate as Longitude and y as Lattitude.

This script is adapted from https://chris35wills.github.io/multi_csv_into_qgis/.
Updated `addAttributeAlias` to `setFieldAlias` as it's renamed.
"""

import os.path, glob

layers = []
path_to_csvs = ""  # file path to all CSVs

for f in glob.glob(path_to_csvs):
    # the source files I used have attributes `Longitude` and `Lattitude`. update the names accordingly.
    uri = "file:///" + f + "?type=csv&xField=%s&yField=%s&spatialIndex=no&subsetIndex=no&watchFile=no&crs=epsg:4326" % ('Longitude', 'Lattitude')
    vlayer = QgsVectorLayer(uri, os.path.basename(f), "delimitedtext")
    vlayer.setFieldAlias(0,'x')
    vlayer.setFieldAlias(1,'y')
    layers.append(vlayer)

QgsProject.instance().addMapLayers(layers)

# this will iteratively add layers to QGIS

qgis-export-layers-geojson.py

"""
Exports current layers in QGIS to GeoJSON files.

This script is adapted from https://gis.stackexchange.com/a/131177
"""
geojsons_dir = ""  # file path to save all GeoJSON files

for vLayer in iface.mapCanvas().layers():
    QgsVectorFileWriter.writeAsVectorFormat( vLayer, 
        geojsons_dir+ vLayer.name() + ".shp", "utf-8", 
        vLayer.crs(), "GeoJSON")

# this will iteratively create GeoJSON files in target directory