def close(self):
# Exit applications
QgsApplication.exitQgis()
QgsApplication.exit()
FOR WINDOWS:
Open the OSGeo Shell and run the python-qgis-ltr.bat file, or just execute python-qgis-ltr.bat from the file explorer
FOR LINUX:
You need to prepare the environment with PYTHONPATH and LD_LIBRARY_PATH variables. For example:
export PYTHONPATH=/docs/dev/qgis/QGIS/3_14_0/output/python/
export LD_LIBRARY_PATH=/docs/dev/qgis/QGIS/3_14_0/lib/
"""
from qgis.core import (QgsApplication, QgsVectorLayer)
# See https://gis.stackexchange.com/a/155852/4972 for details about the prefix
# Hint: print(QgsApplication.showSettings())
QgsApplication.setPrefixPath('/docs/dev/qgis/QGIS/3_14_0/output', True)
qgs = QgsApplication([], False) # No GUI
qgs.initQgis()
airport_layer = QgsVectorLayer(
"/docs/tr/qgis_col/eventos/talleres/Semana_ICG_2019/data/sample_data_4326.gpkg|layername=Airports",
"airport", "ogr")
print("\n\n\n############### RESULTADOS ####################")
print("\nLayer is valid:", airport_layer.isValid())
print("Layer CRS:", airport_layer.crs().description())
print("Layer's feature count:", airport_layer.featureCount())
print("\n NOMBRE \t\t\t GEOMETRÍA")
for f in airport_layer.getFeatures():
print(f['name'], '\t\t\t', f.geometry().asWkt())
print("\n\n\n#############################################")
qgs.exit()
from qgis.core import QgsApplication from PyQt5.QtWidgets import QDialog GUIEnabled = True app = QgsApplication([], GUIEnabled) dlg = QDialog() dlg.exec_() app.exit(app.exec_())
def convert_qgis_gpkg_to_kml(qgs_file: str, output_kml_path: str, stage_dir: str = None) -> str:
app = None
driver_name = "libkml"
try:
from qgis.core import QgsApplication, QgsProject
# Load application to load QApplication dependencies.
app_directory = stage_dir # hosts various session type files like qgis.db etc...
app = QgsApplication([], False, app_directory)
app.initQgis()
# Application needs to be initialized before importing.
from qgis.core import QgsVectorFileWriter
# Load project from template output.
project = QgsProject.instance()
if not project.read(qgs_file):
raise Exception(f"Could not read from {qgs_file}")
layers = project.mapLayers()
symbology_scale = 20000
if stage_dir:
output_dir = os.path.join(stage_dir, "kml")
else:
output_dir = os.path.join(".", "kml")
kml_files = []
for layer_name, layer in layers.items():
output_filename = f"{layer.source().partition('layername=')[2].split('|')[0]}.kml"
output_filepath = os.path.join(output_dir, output_filename)
kml_files.append(output_filename)
if not os.path.exists(output_dir):
os.mkdir(output_dir)
QgsVectorFileWriter.writeAsVectorFormat(
layer=layer,
fileName=output_filepath,
fileEncoding="utf-8",
driverName=driver_name,
symbologyExport=QgsVectorFileWriter.SymbolLayerSymbology,
symbologyScale=symbology_scale,
)
out_driver = ogr.GetDriverByName(driver_name)
if os.path.exists(output_kml_path):
out_driver.DeleteDataSource(output_kml_path)
out_driver.CreateDataSource(output_kml_path)
# Ensure the land_polygons and boundary layers are at the bottom when the files get merged.
try:
kml_files.append(kml_files.pop(kml_files.index("land_polygons.kml")))
kml_files.append(kml_files.pop(kml_files.index("boundary.kml")))
except ValueError as ve:
logger.warning(ve)
# Merge all of the KML files into a single file.
for kml_file in kml_files:
kml_path = os.path.join(output_dir, kml_file)
gdal.VectorTranslate(output_kml_path, kml_path, accessMode="append")
return output_kml_path
finally:
if app:
app.exit()