Using "selectbyexpression" command in standalone PyQGIS script

Question

Is it possible to run "selectbyexpression" in a standalone PyQGIS script? Inside QGIS, I was using iface to add the map to the interface and now I don't know how to run it without using iface.

Answer 1

You could use an expression to get the only the features you want.

request = QgsFeatureRequest().setFilterExpression('my_field > 20')
for feature in vector_layer.getFeatures(request):

see also https://nyalldawson.net/2016/10/speeding-up-your-pyqgis-scripts/