topic Re: Problem creating function containing CalculateField in Python Questions

Problem creating function containing CalculateField

TimPennington — Sun, 11 Feb 2024 03:59:02 GMT

I am very new to both arcgis and python. I am trying to define a function that takes in an input shape file, 2 fields from the file to perform a calculation on, a new field in the file to store the calculation, and an output shapefile name.

I have set up the following in Jupyter:

When I call the function:

I get the following error:

If I add lines to the function to print the inputs, and comment out CalculateField I get :

!Height!

!Area!

!Volume!

I have also tried just passing field 1 and field 2 into CalculateField and I get the same error.

If I run CalculateField without using the function, it runs with expected results.

I am not sure what I need to do to pass the parameters of the function through CalculateField.

Any guidance available would be greatly appreciated. Thank You!

Re: Problem creating function containing CalculateField

AlfredBaldenweck — Mon, 12 Feb 2024 14:44:49 GMT

Try using an f-string:

arcpy.management.CalculateField(dataset_out, input3, f"int({input1})* int({input2})")

The f-string will sub in a variable into the string, just like using "int({})* int({})".format(input1, input2)

~~(I think that's the syntax for the old way? I don't use it anymore.)~~ Okay, that was actually a correct way lol.

Re: Problem creating function containing CalculateField

BlakeTerhune — Mon, 12 Feb 2024 17:21:44 GMT

I think @AlfredBaldenweck is correct here. You could also format your field names with the exclamations in this f-string instead of as separate variables. Also, the second parameter (field) doesn't need the exclamations.

arcpy.management.CalculateField(dataset_out, field3, f"int(!{field1}!) * int(!{field2}!)")

Re: Problem creating function containing CalculateField

TimPennington — Tue, 13 Feb 2024 00:23:57 GMT

Thank you so much for this! Took care of my issue!

Re: Problem creating function containing CalculateField

TimPennington — Tue, 13 Feb 2024 00:24:18 GMT

Thank you very much for helping with this!