test_temp

test_temp.py

# Iterating over the input layer :
for m in municip.getFeatures():
    inh_center = m['EWZ'] 
    # 
    # central municipalites with 0 inhabitants must be excluded; the value of "center_pos" will be set to -1.
    if inh_center == 0:
        center_pos = -1
        dict = {m.fieldNameIndex('center_pos'):center_pos}
        municip.dataProvider().changeAttributeValues({m.id(): dict}) \
        # 
        # Extract by location:
    else:
        key = m['AGS']
        selection_expression = '\"AGS\" = ' + str(key)
        municip.selectByExpression(selection_expression,QgsVectorLayer.SetSelection)
        result = processing.run("qgis:extractbylocation",{'INPUT':QgsProcessingFeatureSourceDefinition(municip.id(),False),'PREDICATE':4,'INTERSECT':QgsProcessingFeatureSourceDefinition(municip.id(),True),'OUTPUT':'memory'})
        extracted = result['OUTPUT']
        count_all = extracted.featureCount()
        countsmall = 0