topic Re: Syntax of subtype values in codeblock in Python Questions

Syntax of subtype values in codeblock

AaronKoelker — Sat, 11 Dec 2021 07:21:53 GMT

I have a pair of data sets with identical schemes; one is a sort of reference layer (A) and the other one is an editable working layer (B). These data sets eventually make their way into a web map for Collector. There is a field using subtypes that help restrict domains for other fields, which looks like:

Code	Description
1	Access
2	Anthropocentric
3	Float
4	Generic Karst
5	Other
6	Outcrop

My workflow includes appending the data in layer (B) to layer (A). The problem is that the subtype field displays its numeric code instead of its description in pop-ups for the web map. For ease of use I need the description to display, so I wanted to calculate the description into a second text field. Eventually this will be a python script, but for testing purposes I've been using the field calculator in ArcMap to check that the code is right before I incorporate it into my larger script. The below example successfully runs without error, but instead of returning the description in my "if" statement, I'm always getting the "else: nope".

Pre-logic script code

def myFunc(ftype_int):
    if (ftype_int == 4):
       return "Generic Karst"
    else:
       return "nope"‍‍‍‍‍‍‍‍‍‍

Expression

myFunc(!FTYPE!)‍

In place of the (ftype_int == 4) I've tried (ftype_int == "4"), (ftype_int == "Generic Karst"), (ftype_int == "4 - Generic Karst"), but# have had no luck.

How do I get the field calculator to properly read the values in the subtype field? Hope this makes sense.

Thanks

Re: Syntax of subtype values in codeblock

DanPatterson_Retired — Wed, 23 Aug 2017 15:30:39 GMT

instead of printing 'nope' print the value it is returning to make sure it is getting the right field

Re: Syntax of subtype values in codeblock

AaronKoelker — Sat, 11 Dec 2021 07:21:55 GMT

def myFunc(ftype_int):
    if (ftype_int == 4):
       return "Generic Karst"
    else:
       ftype_int‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

myFunc(!FTYPE!)‍‍

Hm, modifying my "else" statement to the above gives me a <NULL> value in my FTYPE field.

Re: Syntax of subtype values in codeblock

DanPatterson_Retired — Wed, 23 Aug 2017 15:48:48 GMT

then !FTYPE! isn't the field or it is populated with <null> I don't suppose Description would be the field?

Re: Syntax of subtype values in codeblock

AaronKoelker — Wed, 23 Aug 2017 16:05:59 GMT

There are only the two fields: "ftype_int" which is the 'short' field that has the subtype values, and "ftype" which is the 'text' field I'm trying to calculate to.

Plugging in some of the other unrelated fields from the table into my "else" statement, I've noticed that everything gives me a <Null> value for my ftype field. The only thing that hasn't given me a <Null> return is telling it to print something specific like "nope".

Thanks for taking the time

Re: Syntax of subtype values in codeblock

AaronKoelker — Wed, 23 Aug 2017 19:55:16 GMT

I ended up using another method because I just couldn't figure out what the heck was wrong here. Didn't seem to be able to read any field I tried, so must not be an issue specific to subtype. Instead I broke it into two steps: calculated the numeric codes into my string field, then used the .replace() function to swap out the codes and descriptions. Would still be curious to know why I couldn't get the if/else statements to work, though.