다음과 같은 방식으로 QGIS 처리 알고리즘을 독립형 (GUI 없음) 모드로 실행할 수 있습니다.
import sys
from qgis.core import (
QgsApplication,
QgsProcessingFeedback,
QgsVectorLayer
)
# See /gis//a/155852/4972 for details about the prefix
QgsApplication.setPrefixPath('/usr', True)
qgs = QgsApplication([], False)
qgs.initQgis()
# Append the path where processing plugin can be found
sys.path.append('/docs/dev/qgis/build/output/python/plugins')
import processing
from processing.core.Processing import Processing
Processing.initialize()
layer1 = QgsVectorLayer('/path/to/geodata/lines_1.shp', 'layer 1', 'ogr')
layer2 = QgsVectorLayer('/path/to/geodata/lines_2.shp', 'layer 2', 'ogr')
# You can see what parameters are needed by the algorithm
# using: processing.algorithmHelp("qgis:union")
params = {
'INPUT' : layer1,
'OVERLAY' : layer2,
'OUTPUT' : '/path/to/output_layer.gpkg|layername=output'
}
feedback = QgsProcessingFeedback()
res = processing.run('qgis:union', params, feedback=feedback)
res['OUTPUT'] # Access your output layer
네이티브 알고리즘
이제 네이티브 알고리즘 (즉, 알고리즘이 C ++로 작성된 네이티브 제공자의 알고리즘)을 사용하려면 처리를 초기화 한 후 제공자를 추가해야합니다.
import sys
from qgis.core import (
QgsApplication,
QgsProcessingFeedback,
QgsVectorLayer
)
from qgis.analysis import QgsNativeAlgorithms
# See /gis//a/155852/4972 for details about the prefix
QgsApplication.setPrefixPath('/usr', True)
qgs = QgsApplication([], False)
qgs.initQgis()
# Append the path where processing plugin can be found
sys.path.append('/docs/dev/qgis/build/output/python/plugins')
import processing
from processing.core.Processing import Processing
Processing.initialize()
QgsApplication.processingRegistry().addProvider(QgsNativeAlgorithms())
layer = QgsVectorLayer('/path/to/geodata/lines.shp', 'my layer', 'ogr')
# You can see what parameters are needed by the algorithm
# using: processing.algorithmHelp("native:extractvertices")
params = {
'INPUT': layer,
'OUTPUT': 'memory:'
}
feedback = QgsProcessingFeedback()
res = processing.run("native:extractvertices", params, feedback=feedback)
res['OUTPUT'] # Access your output layer