UniqueValueRenderer method removeValues and addValues does not work correctly if the heading is a blank string

ccowin_odfw

Hello,

Not sure if I'm doing this wrong but to me this seems like this should work just fine but I get the following error:

 

SystemError: <built-in method addValues of MappingSymbologyObject object at 0x00000151F8882670> returned NULL without setting an error

 

 

The code is as follows:

 

p = arcpy.mp.ArcGISProject(path-to-aprx)
mapList = p.listMaps()

for m in mapList:
    layerList = m.listLayers()

    for layer in layerList:
        sym = layer.symbology

        if hasattr(sym, 'renderer'):
            if sym.renderer.type == 'UniqueValueRenderer':
                groupName = sym.renderer.groups[0].heading

                sym.renderer.removeValues({groupName: ['Spring2022']})
                layer.symbology = sym

                sym.renderer.addValues({groupName: ['Fall2022']})
                layer.symbology = sym

 

 

When I go manually into the aprx and change the headings to not a blank string it works fine.

RogerDunnGIS

Great!  Please mark my response as a solution as a kind gesture for my time.  And good luck with all your GIS efforts to make a great web map!!