Splitting vector layer by selected features using PyQGIS

Question

With PyQGIS I'm trying to split selected features into another vector layer using the Split layer function

The code I have is:

area_layer = map.gpkg
fpath_v = C:/output dirctory/filename.gpkg
processing.run("native:splitvectorlayer", {'INPUT':QgsProcessingFeatureSourceDefinition(area_layer, selectedFeaturesOnly=True, featureLimit=-1, geometryCheck=QgsFeatureRequest.GeometryAbortOnInvalid),'FIELD':'Code','PREFIX_FIELD':False,'FILE_TYPE':0,'OUTPUT':'fpath_v'})

But this produces the following error:

File "C:\PROGRA~1\QGIS33~1.3\apps\Python39\lib\code.py", line 90, in runcode
 exec(code, self.locals)
 File "<input>", line 1, in <module>
 File "<string>", line 28, in <module>
TypeError: QgsProcessingFeatureSourceDefinition(): arguments did not match any overloaded call:
 overload 1: argument 1 has unexpected type 'QgsVectorLayer'
 overload 2: argument 1 has unexpected type 'QgsVectorLayer'
 overload 3: argument 1 has unexpected type 'QgsVectorLayer'

I'm not sure how to troubleshoot or go about fixing this.

• Matt: Please provide a minimum working example of your code. map.gpkg will give a syntax error. And please specify where you make your selection. When you use only a filepath as the source, QGIS is not aware of any selection, it should be a selection made on a QgsVectorLayer within the current project.
• Taras: Please, do not forget about "What should I do when someone answers my question?"

Answer 1

The only issue I've seen is about syntax errors in your Python code.

Try the following:

area_layer_path = 'map.gpkg'
fpath_v = 'C:/output directory/filename.gpkg'
fieldname = 'Code'
vlayer = iface.addVectorLayer(area_layer_path, 'demo', 'ogr')
result = processing.run("native:splitvectorlayer", {
 'INPUT': QgsProcessingFeatureSourceDefinition(vlayer.id(), selectedFeaturesOnly=True, featureLimit=-1, geometryCheck=QgsFeatureRequest.GeometryAbortOnInvalid),
 'FIELD': fieldname,
 'PREFIX_FIELD': False,
 'FILE_TYPE':0,
 'OUTPUT': fpath_v
})
# will show an OUTPUT_LAYERS empty if selectedFeaturesOnly=True used but not selected before
print(result)

As mentioned in the comment, you may need to set a selection manually or automatically on the layer before executing the processing.run(... part. Otherwise, selectedFeaturesOnly=True may cause issues.