Exporting attributes table to csv from shp using PyQGIS 2.18?

Question

I'm approaching now for the first time to Python console and I wanted to know step by step how to export in .csv two fields from the attribute table of a vector shapefile(.shp) using just PyQgis. Let's say that up to now I have edited as follows:

fn = "file path"
vlayer = iface.addVectorLayer(fn, "file path", "ogr")
features = vlayer.getFeatures()
for feature in features:
    print (feature [field], feature [2])

layer = QgsVectorLayer(fn, "ogr")
QgsVectorFileWriter.writeAsVectorFormat (layer, r "C: / path of file / filename_csv", "utf-8", None, "CSV", layerOptions = ['GEOMETRY = AS_XYZ']))

From this I get a .csv file but empty, how should I proceed?

Answer 1

I think this is the minimum required to export a shapefile to csv format:

file_path = "path/to/input.shp"
layer = QgsVectorLayer(file_path, "any_name", "ogr")
QgsVectorFileWriter.writeAsVectorFormat(layer, "path/to/output.csv", "utf-8", None, "CSV", layerOptions = ['GEOMETRY=AS_XYZ'])

---

Notice that for the layerOptions, there should not be any spaces inside the string:

E.g.

layerOptions = ['GEOMETRY = AS_XYZ']

Should instead be written as:

layerOptions = ['GEOMETRY=AS_XYZ']