Change point symbol to an existing single marker symbol in PyQGIS

Question

I have a code that takes a polygon layers and returns a temp point layer, I want to change the symbology for the point layer to the "topo pop capital" point symbol through Python.

fn = "C:/Users/Public/Desktop/OSGeo4W/bigBoi.shp"

layer = QgsVectorLayer (fn)

feats = layer.getFeatures()

vl = QgsVectorLayer("Point", "temp", "memory")
pr = vl.dataProvider()


for feat in feats:
    geom =feat.geometry()
    geomSingleType = QgsWkbTypes.isSingleType(geom.wkbType())
    if geom.type() == QgsWkbTypes.PolygonGeometry:
        if geomSingleType :
            x = geom.asPolygon()
            for i in x:
                for y in i:
                    for q in y:
                        f = QgsFeature()
                        f.setGeometry(QgsGeometry.fromPointXY(q))
                        pr.addFeature(f)
                        vl.updateExtents() 
                        QgsProject.instance().addMapLayer(vl)       

        else:
            x = geom.asMultiPolygon()
            for i in x:
                for y in i:
                    for q in y:                         
                        print(q)                   
                        f = QgsFeature()
                        f.setGeometry(QgsGeometry.fromPointXY(q))
                        pr.addFeature(f)
                        vl.updateExtents() 
                        QgsProject.instance().addMapLayer(vl)

I found the setSymbol fucntion that takes a symbol and renders it on a layer like so:

symbol = QgsMarkerSymbolV2.createSimple({'name': 'square', 'color': 'red'})
layer.rendererV2().setSymbol(symbol)

I also found that you can "copy symbol" by right clicking on an existing layer with the desired symbol, but that returns an HTML-like code which for some reason I can't paste here.

Is there a way to create the symbol with the copy symbol output as an object? Is the topo pop capital a symbol layer? And if so how do I appendSymbolLayer() if I don't know how to reference it. Can I call to the symbols from the single symbol favorites? Or maybe export the symbol to get it in Python template?

Answer 1

You could use the following to set the layer style to an existing one in the style database:

layer = iface.activeLayer()
get_styles = QgsStyle.defaultStyle()
style = get_styles.symbol('topo pop capital')

# Apply style and refresh symbology
layer.renderer().setSymbol(style)
layer.triggerRepaint()
iface.layerTreeView().refreshLayerSymbology(layer.id())