topic Re: ArcPro Calculate Field with Python Error in ArcGIS Pro Questions

ArcPro Calculate Field with Python Error

StephanieOosterhouse — Tue, 28 Jan 2025 17:58:58 GMT

Hello,

I am trying to calculate a field with a constant text string and sequential numbering with leading zeros. I have used this expression and code block previously and been successful but now I am getting an error that it cannot find a function that matches the text string. Obviously, there would not be a function matching my text string, but I am not sure why it is not being recognized as a string with the ' '.

Any help would be appreciated. Thanks!

Expression: 'ARC-DOOR-STN-' + "{:0>5}".format(SequentialNumber())

Code Block:

# Calculates a sequential number
# More calculator examples at esriurl.com/CalculatorExamples
rec=0
def SequentialNumber():
global rec
pStart = 669
pInterval = 1
if (rec == 0):
rec = pStart
else:
rec = rec + pInterval
return rec

#change pstart to last ID number#

Re: ArcPro Calculate Field with Python Error

DavidPike — Tue, 28 Jan 2025 18:17:29 GMT

It's probably just an Arcism if it worked before. Easiest fix might be to just put everything into the code block return.

Re: ArcPro Calculate Field with Python Error

DanPatterson — Tue, 28 Jan 2025 18:23:04 GMT

# code block rec=0 st = 'ARC-DOOR-STN-' + "{:0>5}" def SequentialNumber(): global rec pStart = 669 pInterval = 1 if (rec == 0): rec = pStart else: rec = rec + pInterval rec = st.format(rec) return rec # expression SequentialNumber() 'ARC-DOOR-STN-00669'

Re: ArcPro Calculate Field with Python Error

StephanieOosterhouse — Tue, 28 Jan 2025 19:45:46 GMT

The expression is now valid but I am getting this error:

This seems like an easy fix but I am not sure where/how to change the int to string. Thank you for your help!

Re: ArcPro Calculate Field with Python Error

Nick_Creedon — Tue, 28 Jan 2025 20:30:12 GMT

I recommend just adding prefix above the sequential code and add it in the return string. This keeps it simple, and I have used it on some hefty datasets. Check out below: you will see I was creating ID's for manholes and their district.

prefix= "6-MH-" rec=0 def SequentialNumber(): global rec pStart = 1 pInterval = 1 if (rec == 0): rec = pStart else: rec = rec + pInterval return prefix + str(rec)

Re: ArcPro Calculate Field with Python Error

StephanieOosterhouse — Tue, 28 Jan 2025 20:59:26 GMT

With a bit of adjusting I was able to add in the leading zeros using this method as well. Here is the code chunk for anyone else who might need it:

prefix= "ARC-ROOM-STN-"
rec=0
def SequentialNumber():
global rec
pStart = 670
pInterval = 1
if (rec == 0):
rec = pStart
else:
rec = int(rec) + pInterval
rec = "{:05}".format(rec)
return prefix + rec

#pStart equals next number in sequence

Thank you!!