I have displayed in a QListWidget several features ranked according to their values from a field named "CODE". Based on this list I would like to select a feature and after a click on a QpushButton to zoom to the extent of this feature in the canvas.

Here is my crude attempt (I am still a beginner):

def append_features_to_QlistWidget (self): #associated to QpushButton_1

    #----------------function sample--------------------

    self.layer = QgsProject.instance().mapLayersByName('my_layer')[0]

    self.selection = []

    for self.feat in self.layer.getFeatures():
        self.attrs = self.feat.attributes()
        self.code= self.attrs[0]
def zoom (self): #associated to QpushButton_2
    inds = [i.text() for i in self.dlg.listWidget.selectedItems()]
    attribute_value = {}
    for i in inds:
        attribute_value[i] = [f for f in self.layer.getFeatures() if f["code"] == i][0]

    ##Other incomplete attempt:
    # ids = [i.id() for i in self.selection] 
    # self.layer.selectByIds(ids)

1 Answer 1


Something like the code below should work (I simplified, cleaned up a bit and added small features) :

class MyQgsWidget(QWidget):

    def __init__(self, lyr_name: str, parent=None):
        super(MyQgsWidget, self).__init__(parent)
        self.vertical_layout = QVBoxLayout()
        self.list_widget = QListWidget(self)
        self.zoom_pushbutton = QPushButton("Zoom !", self)
        self.layer = QgsProject.instance().mapLayersByName(lyr_name)[0]
        self.layer_feats = []

    def load_layer_feats(self):
        self.layer_feats = [
            (feat.id(), str(feat.attribute("code"))) for feat in self.layer.getFeatures()
        self.list_widget.addItems([code for _, code in self.layer_feats])

    def zoom(self):
        sel_ids = [
            featid for featid, code in self.layer_feats if code == self.list_widget.currentItem().text()

w = MyQgsWidget("my_layer")
  • Awesome ! Merci beaucoup :) ! Could you just clarify why did you add for _, and featid for featid since we don't use it afterwards ?
    – wanderzen
    Mar 5, 2021 at 7:58
  • 1
    code for _, code: we just want to have a list of codes, so we don't need feature ID (_). featid for featid, code in self.layer_feats: we want a list of features ID, so featid is mandatory here and code because we used it in the condition if code == self.list_widget.currentItem().text(). Mar 5, 2021 at 8:15
  • Ok thanks for the explanation ! But I was just wondering why we have to use featid instead of feat.id() ?
    – wanderzen
    Mar 5, 2021 at 8:28
  • I just created a smaller subset of layer features data in self.layer_feats that is a list of features IDs and "code" field values. So, I think it's faster to iterate (but I don't speedtest it with self.layer.getFeatures()). Mar 5, 2021 at 8:34
  • Aaaah got it now ! Thanks !
    – wanderzen
    Mar 5, 2021 at 8:56

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