Error Updating the Attributes value

Question

The code below is not working: This code doesn't affect the table at all

layer = point_layer3
selected_feature = layer.selectedFeatures()
print(len(selected_feature))
layer.startEditing()

for feature in selected_feature:
    a = f['parkeer_approx']

    b = parking_capacity[f.id()-int(1)]['parking_capacity']
    feature["parkeer_approx"] = a - b
    layer.updateFeature(feature)

layer.commitChanges()

Possible duplicate of How to update the attribute table of feature using PyQGIS? — vagvaf, Aug 01 '19 at 13:11
Do you get an actual python error or the code just doesn't update the attribute values? — vagvaf, Aug 01 '19 at 13:13
What errors do you recieve when you run it? I'm pretty sure it should be a = feature['parkeer_approx']. What are you trying to calculate with b? — Joseph, Aug 01 '19 at 13:14
a and b are the no of parkings actually where a is total parkings and b is alloted parking for that specific id so i want the total - alloted to be updated in the table — Chetan Vashisth, Aug 02 '19 at 03:39
You got it right @vagvaf there is no actual python error but the code seems not to be working — Chetan Vashisth, Aug 02 '19 at 03:44
I found the issue guys. The laye which i was using is not allowed to be edited so that's the reason why i wasn't able to update that layer. So thanks for the response guys .... later.... — Chetan Vashisth, Aug 02 '19 at 05:22

score 3 · Accepted Answer · answered Aug 01 '19 at 13:22

Similar to what @Joseph pointed out in the comments, in the lines where you set a and b did you mean to use "f" instead of "feature"? Try the updates below:

for feature in selected_feature:
    a = feature['parkeer_approx']

    b = parking_capacity[feature.id()-int(1)]['parking_capacity']
    feature["parkeer_approx"] = a - b
    layer.updateFeature(feature)

Error Updating the Attributes value

1 Answers1