topic Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working in ArcGIS Pro Questions

ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

SaranehSFitzgerald — Thu, 29 May 2025 15:47:46 GMT

def RampQA(ramp_type😞

if ramp_type is None:

return "Ramp type is blank"

This hasnt worked, but feels like it should be simple... "ramp_type" is a string field. This calculation would return an error in a completely different field. Instead of returning "Ramp type is blank" it just returns Null in that field and results in this warning message:

WARNING 002858: Certain rows set to NULL due to error while evaluating python expression: File "<string>", line **, in RampQA

Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

DavidPike — Thu, 29 May 2025 15:55:38 GMT

Can you post a screengrab of the expression and codeblock from Pro? Also your text got formatted into an emoji.

Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

KenBuja — Thu, 29 May 2025 16:00:27 GMT

Are the values Null, an empty string (""), or a space (" ")?

Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

RichardHowe — Thu, 29 May 2025 16:32:38 GMT

Your expression for the above code block would need to be:

RampQA(!ramp_type!)

Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

AustinAverill — Thu, 29 May 2025 17:17:08 GMT

This is likely the root. Trying to verify "blank" values in field calculator is a mess.

Re: ArcGIS Pro Calculate Field Using Python - Return String if Field is Null not working

JoshuaBixby — Thu, 29 May 2025 18:04:17 GMT

You don't even need a code block for this, a Python 6.13. Conditional expressions in the expression block will do the trick:

"Ramp type is blank" if !ramp_type! is None else !ramp_type!