Splitting a vector layer by selected features using PyQGIS

Question

I'm new to 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

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.