How to access raster classification alias from layer

[DonMorrison1]

I'm creating a python toolbox geoprocessing tool that will take a raster map layer as input (USA NLCD Land Cover), do some analysis on it, and generate a report - basically tabulating the acreage of the different land cover types (eg. open water, barren land, mixed forest...) for a given area. In the report I'd like to show the classification labels, but I can only see how to access the actual numeric pixel values (eg. 1,2,3, etc).  I assumed I could get this throught the layer's symbology, but I'm not seeing it.  How can I use arcpy to find the mapping from numeric classification to the text label, starting from a Layer object? 

[Marshal · Accepted solution]

You can retrieve this by using the CIM definition properties of the raster layer.  More specifically, using the colorizer property.  I assumed you are using the Unique Values symbology type.

import arcpy

# Access the current ArcGIS Pro project and the specific map and raster layer
project = arcpy.mp.ArcGISProject("CURRENT")
map_obj = project.listMaps("YourMapName")[0]  # Replace "YourMapName" with your map name
raster_layer = map_obj.listLayers("YourRasterLayerName")[0]  # Replace with your raster layer's name

# Get the CIM definition of the raster layer
cim_def = raster_layer.getDefinition('V3')

# Check if the colorizer is of type CIMRasterUniqueValueColorizer
if isinstance(cim_def.colorizer, arcpy.cim.CIMRasterUniqueValueColorizer):
    # Access the Unique Value Colorizer properties
    unique_value_colorizer = cim_def.colorizer
    
    # Iterate through each unique value class in the first group
    for unique_value_class in unique_value_colorizer.groups[0].classes:
        label = unique_value_class.label
        values = unique_value_class.values  # List of values for this unique class
        color = unique_value_class.color  # RGBA color as a CIMColor object
        
        print(f"Label: {label}")
        print(f"Values: {values}")
        print(f"Color: RGBA({color.values[0]}, {color.values[1]}, {color.values[2]}, {color.values[3]})")
        print("----")
else:
    print("The raster layer does not have a CIMRasterUniqueValueColorizer applied.")

[DonMorrison1]

Thanks @Marshal!