Making Python script originally produced with QGIS Modeler work on QGIS console

Question

I'm writing some scripts on QGIS Python console, and I would like to implement some dialog windows, as those about the parameters' insertment, converting from the result of model builder, but when I copy and paste the script on console, this doesn't work.

How can I solve this problem?

Here the code of an example script from the modeler.

from qgis.core import QgsProcessing
from qgis.core import QgsProcessingAlgorithm
from qgis.core import QgsProcessingMultiStepFeedback
from qgis.core import QgsProcessingParameterVectorLayer
from qgis.core import QgsProcessingParameterNumber
from qgis.core import QgsProcessingParameterFeatureSink
from qgis.core import QgsExpression
from qgis.core import QgsVectorLayer
from qgis.core import QgsFeatureRequest
import processing
class Modello(QgsProcessingAlgorithm):
 def initAlgorithm(self, config=None):
 self.addParameter(QgsProcessingParameterVectorLayer('comuneselezionato', 'ComuneSelezionato', types=[QgsProcessing.TypeVectorPolygon], defaultValue=None))
 self.addParameter(QgsProcessingParameterNumber('intensit_terremoto', 'Intensità Terremoto', optional=True, type=QgsProcessingParameterNumber.Double, minValue=3, maxValue=12, defaultValue=None))
 self.addParameter(QgsProcessingParameterNumber('distanza_dallepicentro', "Distanza dall'epicentro", type=QgsProcessingParameterNumber.Integer, minValue=15000, maxValue=200000, defaultValue=None))
 self.addParameter(QgsProcessingParameterFeatureSink('Evidenziaedifici', 'EvidenziaEdifici', type=QgsProcessing.TypeVectorAnyGeometry, createByDefault=True, defaultValue=None))
 def processAlgorithm(self, parameters, context, model_feedback):
 # Use a multi-step feedback, so that individual child algorithm progress reports are adjusted for the
 # overall progress through the model
 feedback = QgsProcessingMultiStepFeedback(4, model_feedback)
 results = {}
 outputs = {}
 # Ritaglia
 alg_params = {
 'INPUT': 'Edifici_filtrati_per_datazione_d5f42b62_efc8_483a_b355_e6013129b596',
 'OVERLAY': parameters['comuneselezionato'],
 'OUTPUT': QgsProcessing.TEMPORARY_OUTPUT
 }
 outputs['Ritaglia'] = processing.run('native:clip', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
 feedback.setCurrentStep(1)
 if feedback.isCanceled():
 return {}
 # Centroidi
 alg_params = {
 'ALL_PARTS': False,
 'INPUT': 'IsosismeTerremotiTotaliA200KmDaToscanaELiguria_b2371c3b_9244_4008_b848_a3a55fbd7353',
 'OUTPUT': QgsProcessing.TEMPORARY_OUTPUT
 }
 layerTerremoti = QgsVectorLayer("alg_params['INPUT']", "terremoti", "ogr")
 intensitaTerr = parameters['intensit_terremoto']
 
 if feedback.isCanceled():
 return {}
 # Buffer
 alg_params = {
 'DISSOLVE': False,
 'DISTANCE': QgsExpression(' @distanza_dallepicentro ').evaluate(),
 'END_CAP_STYLE': 0, # Arrotondato
 'INPUT': outputs['Centroidi']['OUTPUT'],
 'JOIN_STYLE': 0, # Arrotondato
 'MITER_LIMIT': 2,
 'SEGMENTS': 5,
 'SEPARATE_DISJOINT': False,
 'OUTPUT': QgsProcessing.TEMPORARY_OUTPUT
 }
 outputs['Buffer'] = processing.run('native:buffer', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
 feedback.setCurrentStep(3)
 if feedback.isCanceled():
 return {}
 # Estrai per posizione
 alg_params = {
 'INPUT': outputs['Buffer']['OUTPUT'],
 'INTERSECT': outputs['Ritaglia']['OUTPUT'],
 'PREDICATE': [0], # interseca
 'OUTPUT': parameters['Evidenziaedifici']
 }
 outputs['EstraiPerPosizione'] = processing.run('native:extractbylocation', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
 results['Evidenziaedifici'] = outputs['EstraiPerPosizione']['OUTPUT']
 return results
 def name(self):
 return 'modello'
 def displayName(self):
 return 'modello'
 def group(self):
 return ''
 def groupId(self):
 return ''
 def createInstance(self):
 return Modello()

• Ben W: This is a processing algorithm script. You can run it from the processing script editor for testing, but the idea of processing scripts is that they are added to the processing toolbox via the Python icon in the toolbar of the processing toolbox dockwidget, or packaged into a processing plugin. They are not intended to be run from the Python console.
• Salvatore Diolosà: So, I can't cut the part that I'm interested in and to paste it in my script written on console?

Answer 1

As was highlighted by @BenW your Python code is a processing algorithm script, that was probably created from a QGIS Model exported as a Python script, see the QGIS Documentation | Exporting a model as a Python script.

I do not know if there is an automatic way to convert this processing algorithm script to a processing Python script, but you can give a try to a manual approach.

By the way one can run the processing algorithm script via:

import processing
from qgis.core import QgsProject
layer = QgsProject.instance().mapLayersByName('POLYGON_LAYER_NAME')[0]
processing.runAndLoadResults("script:modello", {
 'comuneselezionato': layer,
 'intensit_terremoto': 3,
 'distanza_dallepicentro': 15000,
 'Evidenziaedifici': 'TEMPORARY_OUTPUT'
})

---

References:

• QGIS Documentation | Creating scripts and running them from the toolbox
• Free and Open Source GIS Ramblings | PyQGIS 101: Writing a Processing script
• Free and Open Source GIS Ramblings | Easy Processing scripts comeback in QGIS 3.6
• QGIS Tutorials and Tips | Writing Python Scripts for Processing Framework (QGIS3)