Delete empty feature class in modelbuilder - "Calculate Value" Expression problems

Question

I am trying to delete empty feature classes created in the process of intersecting layers with a set-up in modelbuilder. By using Calculate Value tool i have written a code that should do the trick.

It is suppose to get count and if it is equal to zero then employ delete_management, which should delete the feature class. Else, do nothing and add a warning.

Some way along, it is not doing what I want. The model is creating my feature classes but even though some of them are empty they are not deleted. The report states that:

" Start Time: Wed Mar 18 11:15:09 2015 WARNING 000117: Warning empty output generated. Succeeded at Wed Mar 18 11:15:20 2015 (Elapsed Time: 11,44 seconds) Executing (Calculate Value): CalculateValue DeleteIfZeroCount(r"M:\HAL\TeamNIS\Tools\SOE_check\Models\Version1\Results\TestIntersectOnWhole.gdb\NaturalFeaturesA_PortsAndServicesA_Intersect") "def DeleteIfZeroCount(inFC) :\n import arcpy\n if int(arcpy.GetCount_management(inFC).getOutput(0)) == 0:\n arcpy.Delete_management(inFC)\n return True\n else:\n arcpy.AddWarning('Error in '+inFC)\n return False" Boolean Start Time: Wed Mar 18 11:15:21 2015 The process did not execute because the precondition is false. Succeeded at Wed Mar 18 11:15:21 2015 (Elapsed Time: 0,00 seconds) "

So, even though the feature class is empty, my Calculate Value tool doesn't delete the feature class. I am a newbie at coding including arcpy, so I might have made an obvious mistake. The question is why it won't delete the empty file? What is wrong with my code? The model and code is shown in the attached image, please state if you need more info.

Code

Example of model an Calculata Value

• Erica: One minor note, even though I do not think it is the cause of your problem: you do not need import arcpy in your code block.
• aneh: Thank for the reply. Though, am I not importing arcpy in the second line in the block?
• Erica: Yes, but you don't need to import the arcpy module if your Python code is running inside ArcMap -- only if externally.
• radouxju: I think that it would be easier if you did it all with a python script . There is probably a conflict here because you use getValue to run a tool that delet a fc which is used by getvalue as input. If you want to use a model, try with the result of your get value as a precondition and put the Delete tool in the main model
• aneh: It actual works now.

Answer 1

Actually, it turns out that I had made an error with my preconditions. The code works and it deletes the empty feature classes. The only thing that now bothers me is that i don't recieve any warning messages arcpy.AddWarninng( 'Error in + 'inFC) .