Getting label feature with PyQGIS?

Question

I need get the label text for each feature in a points layer. I can read feature attribute using:

layer = QgsProject.instance().mapLayersByName('layer_name')[0]
features = layer.getFeatures(QgsFeatureRequest())
for f in features:
    attribute=f.['field_name']

but I need the label text (result of a expresion), it's diferent from attribute.

Answer 1

You can get the label text for each feature this way in QGIS 3:

layer = iface.activeLayer()

if layer.labelsEnabled():
    labeling = layer.labeling()
    palyr = labeling.settings()
    expression = QgsExpression(palyr.fieldName)

    context = QgsExpressionContext()
    for feature in layer.getFeatures():
        context.setFeature(feature)
        expression.prepare(context)
        value = expression.evaluate(context)
        print(expression.formatPreviewString(value, True))