Specifying Resource Field For Labeling in ArcPy with ArcMap

Question

How do I specify which field acts as resource for labeling a layer using ArcPy?

Following code is some settings that I am doing on a standalone ArcPy snippet and as you can see I added layer.showLabels = True but assuming I have a field named name I do not know how to add it to the code.

layer = arcpy.mapping.Layer("Primary")
layer.minScale = 10000
layer.showLabels = True

Answer 1

Once you have the label class object set the expression using the expression property:

expression: Provides the ability to get or set a layer's individual label class expression. This can be as simple as a single field or more advanced using either a VBScript, JScript or Python expression.

for lblClass in lyr.labelClasses:
 if lblClass.showClassLabels:
 lblClass.expression = lblClass.expression = "\"<FNT name='Arial' size='12'>\" & [MyFieldNameHere] & \"</FNT>\""

Answer 2

As commented by @MichaelStimson:

You need to specify a labelClass object https://resources.arcgis.com/en/help/main/10.2/index.html#/LabelClass/00s30000002t000000/ - even if you have only one class, look at the example in the link.