I can't stop getting this error message when I try to run the following code in Qgis 2.14.10 :

from qgis.core import *
from PyQt4.QtCore import *
from PyQt4.QtCore import QSettings
from PyQt4.QtCore import QSettings
from qgis.core import QgsVectorLayer, QgsDataSourceURI

uri = QgsDataSourceURI()
uri.setConnection("localhost", "5432", "name of my database", "my user name", "my password")
uri.setDataSource("database schema", "table name", "geom")
couche = "PM"
layer = QgsVectorLayer(uri.uri(), couche, "postgres")
if not layer.isValid:
    print ('Chargement de la couche: echec !')

TypeError: QgsMapLayerRegistry.addMapLayers(list-of-QgsMapLayer, bool addToLegend=True): argument 1 has unexpected type 'QgsVectorLayer'

Could someone tell me what I'm doing wrong please ? :)

1 Answer 1


You are trying to add a single layer using a function designed for adding multiple layers.

Either use


or put the single layer into a (single element) list

  • 1
    Damn it I'm sorry ! I went through all the lines of my script again and again but I couldn't see that tricky "s" ! :) Thanks !!!
    – wanderzen
    Dec 17, 2020 at 15:13
  • 1
    Happens to everyone, at least two times. Dec 17, 2020 at 16:11

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