How do I update existing field with a common number using Field Calculator Python console in QGIS 2.18.10?
I have tried:
processing.runalg('qgis:fieldcalculator', layername, "fieldname", 2, 20, 0, False, "3", path+"mynewlayer")
But my concern is each time I want to update a column I would have to create a new output layer. Is there a way of updating field without creating new or am I missing something?