ArcPro ArcPy defined function not resetting symbology reference parameter in subsequent function calls

JillMasters1

The following code works beautifully the first time the function is called. The second time the function is called, the new second parameter value, Forest_TmbrVol_Source, is ignored while the new first parameter value, Project_TmbrVol_Path, is correctly used.

The result is that in both function calls, the input layer is symbolized by the same Forest_SlopePrc_Source symbology, which in the second call, results in Timber Volume being symbolized with Slope Percentage symbology rather than Timber Volume symbology as coded.

This error is not a result of duplicate names or incorrectly called vars. I coded messages to return the values of what was passed and processed and there are no errors there. The problem appears to be the persistence of the same initial variable used in the ApplySymbologyFromLayer tool for the reference symbology raster.

Reversing the order of the two calls, does not change this behavior. The mismatch in the 2nd call continues, but reversed., such that the input layer is incorrectly symbolized by Forest_TimbVol_Source rather than Forest_SlopePrc_Source symbology as coded.

 

Image content:

#function

def apply_symbology(target_raster, symb_raster):

#apply symbology

target = current_map.addDataFromPath(target_raster)

symbLayer = current_map.addDataFromPath(symb_raster)

symb=symbLayer.listLayers()[2]   #returns Raster Image

outlayer = arcpy.management.ApplySymbologyFromLayer(target, symb)

current_map.addLayer(outlayer[0])

 

#var assignments

proj_folder=r'C:\Project\LayerFile\Clipped'

Forest_SlopePrc_Source = r'C:\Project\LayerFile\ImageryAndClassifiedImagery\LiDAR_1m_BareEarth_SlopePct_Color.lyr'

Forest_TmbrVol_Source = r'C:\Project\LayerFile\ImageryAndClassifiedImagery\LiDAR_30m_modeled_Volume_boardft_gt_9in_per_acre.lyr'

Project_SlopePrc_Path = proj_folder + '\\Project_SlopePrc'

Project_TmbrVol_Path = proj_folder + '\\Project_TmbrVol'

 

#function call

apply_symbology(Project_SlopePrc_Path, Forest_SlopePrc_Source)

apply_symbology(Project_TmbrVol_Path, Forest_TmbrVol_Source)

 

 

DanPatterson

Apply Symbology From Layer (Data Management)—ArcGIS Pro | Documentation

The "optional" parameter describes the situations where symbology won't be updated.  

Can you confirm that this doesn't apply?

 

Update_symbology
(Optional)
Specifies whether symbology ranges will be updated.

DEFAULT—Symbology ranges will be updated, except in the following situations:
When the input layer is empty
When the symbology layer uses class breaks (for example, graduated colors or graduated symbols) and the classification method is manual or defined interval
When the symbology layer uses unique values and the Show all other values option is checked
UPDATE—Symbology ranges will be updated.
MAINTAIN—Symbology ranges will not be updated; they will be maintained.

As for code formatting to facilitate reading and line number referencing, have a look at...

Code formatting ... the Community Version - Esri Community