Changing the value of attributes using QgsFeature in PyQGIS

Question

The script doesn't work as if I wanted.

Script:

mylayer = QgsProject.instance().mapLayersByName("Kuniarka")[0]
dane = 'a'
for seg in mylayer.getFeatures():
    #seg = next (mylayer.getFeatures())
    seg["WSP_X"] = dane
    mylayer.updateFeature(seg)

Effect:

Desired effect:

Script improvisation:

mylayer = QgsProject.instance().mapLayersByName("Kuniarka")[0]
dane = ["a", "b"]
for seg in mylayer.getFeatures():
    #seg = next (mylayer.getFeatures())
    seg["WSP_X"] = dane
    mylayer.updateFeature(seg)

Script improvisation2:

mylayer = QgsProject.instance().mapLayersByName("Kuniarka")[0]
for feat in mylayer.getFeatures():
    dane = ["a", "b"]
    mylayer.changeAttributeValue(feat.id(), 3, dane)

Script doesn't work correctly.

https://gis.stackexchange.com/questions/427212/changing-the-value-of-attributes-using-geocoding-in-pyqgis — Artur Arturo, Mar 27 '22 at 18:49

score 5 · Accepted Answer · answered Mar 27 '22 at 13:28

I think you're looking to access the list index.

dane = ['a', 'b']
print(dane[0]) #prints 'a'

In your code this would give (there are better ways in python to loop over 2 iterators):

from qgis.core import *
mylayer = QgsProject.instance().mapLayersByName("point1")[0]
dane = ['a', 'b', 'c', 'd', 'e']
i = 0
with edit(mylayer):
    for seg in mylayer.getFeatures():
        #seg = next (mylayer.getFeatures())
        print(seg.id())
        seg['name'] = dane[i]
        i += 1
        mylayer.updateFeature(seg)

Changing the value of attributes using QgsFeature in PyQGIS

1 Answers1