Getting all layer names from opened .qgz project file using PyQGIS

Question

I have several .qgz project in different directories. I would like to get all the (displayed) layer names from each project. I tried several forms of code to get it from documentation, but it only returns an empty list in each file.

for settlement in os.listdir(source):
    settlement_path = os.path.join(source, str(settlement))
    settlement_name = str(settlement)

    for qgz in os.listdir(settlement_path):
        if str(qgz).endswith('.qgz'):
            project = QgsProject.instance()
            project.read(str(qgz))
            layers_names = []

            for layer in project.mapLayers().values():
                layers_names.append(layer.name())
            print(layers_names)

        project.clear()

Answer 1

You miss os.path.join in the second loop.

Change

project.read(str(qgz))

to

project.read(os.path.join(settlement_path, str(qgz)))