So, I'm genuinely confused by this.
I have a python script tool that needs to go find a SID file in our directory, pull it into the map, and add it to an already-existing Group Layer.
The Group Layer is provided to the tool by the user.
Simplified code below:
aprx = arcpy.mp.ArcGISProject('CURRENT')
mxd = aprx.activeMap
recordLayerGrp = arcpy.GetParameter(7) # Note that I'm not pulling as Text;
# this comes through as an
# arcpy.mp.Layer object
# [... intermediate code where I work with this and other layer objects just fine...]
mxd.addLayerToGroup(recordLayerGrp, # At the point the function gets this
# variable, it's unchanged from input;
# I pass it directly from the input
# function to this function.
fileLayerObj, # This is also an arcpy.mp.Layer object
'TOP',
) This consistently fails with a ValueError. After a bunch of headache, I managed to determine that said error is referencing the arcpy.mp.Layer object behind recordLayerGrp.
I went and did quite a bit of spelunking on this issue yesterday and today, and finally added a single line to the code (line 2, below):
recordLayerGrp = arcpy.GetParameter(7)
recordLayerGrp = [lyr for lyr in mxd.listLayers() if lyr.name == recordLayerGrp.name][0]
The result of this is still an arcpy.mp.Layer object, but it's a different instance. And this different one suddenly magically works. I even added debug statements before and after line 2, to see what was in recordLayerGrp at each step:
The tool inputs directly ask for the Group Layer and the user selects it. Why did I have to "convert" the arcpy.mp.Layer object and go look for that Group Layer again? Why doesn't the tool pull the "correct" instance of that object?
