AttributeError: 'QgsVectorLayer' object has no attribute 'fieldNameIndex'

Question

When I try to calculate a new field with:

idx = layer.fieldNameIndex(attributeName)

I receive the following error:

AttributeError: 'QgsVectorLayer' object has no attribute 'fieldNameIndex'

What´s the problem? I'm using QGIS 3.0.1 64x in Windows.

Please, do not forget about "What should I do when someone answers my question?" — Taras, Nov 19, 2022 at 11:25

Taras · Accepted Answer · 2022-11-19 11:41:50Z

19

In PyQGIS 3

Use one of the following methods from the QgsFields class:

layer = iface.activeLayer()
layer_fields = layer.fields()
field_index = layer_fields.indexFromName("FIELD_NAME")

layer = iface.activeLayer()
layer_fields = layer.fields()
field_index = layer_fields.lookupField("FIELD_NAME")

layer = iface.activeLayer()
layer_fields = layer.fields()
field_index = layer_fields.indexOf("FIELD_NAME")

Taras

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answered Jun 20, 2018 at 9:45

user122730

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Taras · Accepted Answer · 2022-11-19 11:37:03Z

7

You need to access it via the fieldNameIndex() method of the QgsVectorDataProvider class:

layer = iface.activeLayer()
idx = layer.dataProvider().fieldNameIndex(attributeName)

Taras

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answered Apr 18, 2018 at 14:14

Joseph

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How do you do that in the Python console? I'm a noob.
– Novvier
Apr 18, 2018 at 16:28
@MarcoUscuchagua - Click on a layer and type layer = iface.activeLayer(). Then type idx = layer.dataProvider().fieldNameIndex("fieldName"). The self` parameter is mainly used for plugins.
– Joseph
Apr 20, 2018 at 9:15
The error remains. I think it is a error of QGIS and not of my layer.
– Novvier
Apr 20, 2018 at 12:17
@MarcoUscuchagua - What error are you receiving? Is it the same error as in your question?
– Joseph
Apr 20, 2018 at 12:34
1

I found the solution!! The problem was in the Quick Attribution plugin, its reinstallation solved the problem. Thanks @Joseph
– Novvier
Apr 24, 2018 at 0:42

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