Save CSV with separator using PyQGIS 3?

Question

I need save selected attributes of layer as CSV with separator. This is my code:

def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterVectorLayer('Input', 'Input', types=[QgsProcessing.TypeFile], defaultValue=None))
        self.addParameter(QgsProcessingParameterFeatureSink('Output', 'Output', type=QgsProcessing.TypeFile, createByDefault=True, defaultValue= '')) 

def processAlgorithm(self, parameters, context, model_feedback):
        feedback = QgsProcessingMultiStepFeedback(1, model_feedback)
        results = {}
        outputs = {}


        alg_params = {
            'FIELDS_MAPPING': [{'expression': 'FID',  
                                'length': 10, 
                                'name': 'FID',  
                                'precision': 0,
                                'type': 10},  
                              ],
                                
            'INPUT': parameters['Input'],
            'OUTPUT':  parameters['Output']
           
           }
           
        results['Result'] = processing.run('qgis:refactorfields', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
        outputs['Outputs'] = results['Result']['OUTPUT']
        crs = QgsCoordinateReferenceSystem("EPSG:5514")
        uri = outputs['Outputs']
        layer = QgsVectorLayer(uri, 'name', 'ogr' )
        
        QgsVectorFileWriter.writeAsVectorFormat(layer, 'C:/Users/xxxx/OneDrive/xxxx', "utf-8", crs, "CSV", layerOptions=["GEOMETRY=AS_YX", "SEPARATOR=SEMICOLON"])  
        
        return outputs

Problem is that the CSV is exported, but with comma not separator.

In layerOptions I have I want separator as delimiter, but it isn´t working. I can´t find mistake, maybe in Output?

Answer 1

Working on my side. I suppose there is a minor difference in your code that breaks your result

To confirm the issue is in your code and not related to QGIS version or specific install issue, you can try this standalone working solution by selecting a point layer and run in the console the following

layer = iface.activeLayer()
QgsVectorFileWriter.writeAsVectorFormat(layer, '/tmp/out_semicolon.csv', "utf-8", layer.crs(), "CSV", layerOptions=["GEOMETRY=AS_YX", "SEPARATOR=SEMICOLON"])

with open("/tmp/out_semicolon.csv") as infile:
    # To confirm you see semicolon separated result
    print(infile.readline())
    print(infile.readline())

QgsVectorFileWriter.writeAsVectorFormat(layer, '/tmp/out_tab.csv', "utf-8", layer.crs(), "CSV", layerOptions=["GEOMETRY=AS_YX", "SEPARATOR=TAB"])

with open("/tmp/out_tab.csv") as infile:
    # To confirm you see tab separated result
    print(infile.readline())
    print(infile.readline())