I have some layers loaded in QGIS, in various groups. I want, with PyQGIS, do some stuff on layers from one of theses groups, like adding geometry type to the layer name.

This way, I can do it on all layers :

layers = QgsProject.instance().mapLayers().values()
for layer in layers:

This way, I can access layer names from one specific group :

root = QgsProject.instance().layerTreeRoot()
my_group = root.findGroup('My group')
for layer in my_group.children():
   if isinstance(layer, QgsLayerTreeLayer):

The "print" of layer name works, but I can't change name, either get the geometry type. I get this error :

AttributeError: 'QgsLayerTreeLayer' object has no attribute 'wkbType'

Does someone know what is the correct way to do that?

  • Do you get any error? – Kadir Şahbaz Sep 21 '20 at 13:51
  • Yes, the Attribute Error (the last line of code in my post) – Cupain Sep 21 '20 at 13:56
  • I missed that. :( – Kadir Şahbaz Sep 21 '20 at 14:09

You should add layer() method to layer object. layer is an instance of QgsLayerTreeLayer. It doesn't have wkbType attribute, but QgsVectorLayer has.

Change layer.wkbType() to layer.layer().wkbType(). layer.layer() returns the map layer associated with layer.

root = QgsProject.instance().layerTreeRoot()
my_group = root.findGroup('My group')
for layer in my_group.children():
   if isinstance(layer, QgsLayerTreeLayer):
      layer.setName(layer.name() + "_" + QgsWkbTypes.displayString(layer.layer().wkbType()))
  • Perfect ! Thank you. – Cupain Sep 21 '20 at 14:09

If each layer of your QGIS project has a unique name, you can use the following code. The loop retrieves the name of the layers of your group then you will identify the layer with the mapLayersByName method and you will be able to manipulate it easily.

root = QgsProject.instance().layerTreeRoot()
my_group = root.findGroup('My group')

layer_list = [layer.name() for layer in my_group.children()]
for layer in layer_list:
    update_layer = QgsProject.instance().mapLayersByName(layer)
    for lay in update_layer:
        lay.setName(lay.name()+"_" +QgsWkbTypes.displayString(lay.wkbType()))
  • Unfortunately, layers can have the same name, and different geometry. For instance, i have "railway_rail" as point, and "railway_way" as line. That's why I want to add the geometry type to the name – Cupain Sep 21 '20 at 13:41
  • "railway_rail" and "railway_way" don't have the same name. So it's ok. – Vincent Bré Sep 21 '20 at 13:45
  • my mistake, railway_rail and railway_rail – Cupain Sep 21 '20 at 13:46
  • I updated my code, it works with your situation. Ask me if you need any explanations – Vincent Bré Sep 21 '20 at 13:59
  • 1
    It works and it's smart, but Kadir Şahbaz' solution is easier and more efficient. Thanks for your help ! – Cupain Sep 21 '20 at 14:08

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