topic Re: ArcPro 2.5 field calculator bug in ArcGIS Pro Questions

ArcPro 2.5 field calculator bug

PRuss — Fri, 01 May 2020 15:07:21 GMT

"\\DPWTECHENG\Plat\" + !plat_book! + "_" + !plat_page! + ".tif"

throws an syntax error in ArcPro 2.5

"\\DPWTECHENG\Plat\ " + !plat_book! + "_" + !plat_page! + ".tif"

is valid in ArcPro 2.5 field calculator, the only difference is adding a space after \Plat\

Problem: We don't want that extra space after \Plat\

any ideas on when this bug will be fixed?

Re: ArcPro 2.5 field calculator bug

Katie_Clark — Fri, 01 May 2020 15:13:31 GMT

I'm not sure, can you use raw strings in field calculator? That might help.

Python Raw String - JournalDev

Does this work for you?

r"\\DPWTECHENG\Plat\" + !plat_book! + "_" + !plat_page! + ".tif"‍

Re: ArcPro 2.5 field calculator bug

PRuss — Fri, 01 May 2020 15:19:58 GMT

same syntax error trying

r"\\DPWTECHENG\Plat\" + !plat_book! + "_" + !plat_page! + ".tif"

Re: ArcPro 2.5 field calculator bug

Katie_Clark — Fri, 01 May 2020 15:31:44 GMT

I was playing around with this a bit, it seems to not like using r for a raw string. Instead, add another backslash as an escape character. (below is the code I used, so keep in mind I'm using all strings instead of referencing field names)

"\\\DPWTECHENG\Plat\\" + "plat_book" + "_" + "plat_page" + ".tif"‍

That validates for me, and the extra backslash isn't included in the output.

Re: ArcPro 2.5 field calculator bug

PRuss — Fri, 01 May 2020 16:12:25 GMT

interesting work around that delivers the correct output, i appreciate your help!

add another backslash as an escape character

i submitted this bug to: support.esri.com/en/report-bug

Re: ArcPro 2.5 field calculator bug

Katie_Clark — Fri, 01 May 2020 17:17:24 GMT

Glad it helped!

For reference, here is a page on escape characters in Python:

Python Escape Characters

I'm not sure if this technically would qualify as a bug (not accepting raw strings in field calculator), but if you do get more relevant information from Esri regarding this, it would be awesome if you'd post back here with an update in case someone references this post in the future.

Cheers,

Katherine

Re: ArcPro 2.5 field calculator bug

PRuss — Fri, 01 May 2020 20:29:30 GMT

It works fine in ArcMap using VBScript:

"\\DPWTECHENG\Plat\" + [plat_book] + "_" + [plat_book] + ".tif"

i have never understood why Pro did away with the VBScript option.... if something works better than alternatives why get rid of it?

Another ArcMap example doing something better than Pro:

Hyperlinks - after 1 input into attribute table they work flawlessly in ArcMap.

in Pro one has to find workarounds for lack of a solid working language (VBScript) and add additional coding e.g.

"<a href=" + [plat] + " target=_top>" + [plat_book] + "_" + [plat_page]

and then once these 2 extra steps are done, there is a significant lag time when clicking the hyperlinks in Pro, often having to click them several times before they open.

I linked this thread to the Report Bug to highlight all of these Pro limitations that need to be fixed.

I know I am not the only one spending way too much time (many hours) diagnosing, finding workarounds, and documenting these unacceptable issues... Esri has had 5 years to get Pro to come correct, starting to think it is never going to happen.

Re: ArcPro 2.5 field calculator bug

DrewFlater — Sat, 02 May 2020 07:58:06 GMT

Instead of trying to figure out how to construct the path with all the \ which are Python escape characters, use the very handy os function, os.path.join():

os.path.join(r"\\DPWTECHENG\Plat", !plat_book! + "_" + !plat_page! + ".tif")

Re: ArcPro 2.5 field calculator bug

JoshuaBixby — Sat, 11 Dec 2021 09:43:10 GMT

P Russ‌, the issue you are running into isn't a defect, either in Field Calculator or Python, it is a misunderstanding of the syntax for Python strings.

Although I support Katherine's suggestion on using raw strings for paths, her first suggestion using a raw string

>>> r"\\DPWTECHENG\Plat\" + !plat_book! + "_" + !plat_page! + ".tif"
  File "<stdin>", line 1
    r"\\DPWTECHENG\Plat\" + !plat_book! + "_" + !plat_page! + ".tif"
                                           ^
SyntaxError: invalid syntax
>>> ‍‍‍‍‍‍

was still invalid because a "a raw literal cannot end in a single backslash" (2. Lexical analysis — Python 3.7.7 documentation ). Although raw strings treat backslashes as normal characters, that doesn't apply when the backslash is the final character in a sequence.

Re: ArcPro 2.5 field calculator bug

JoshuaBixby — Sat, 02 May 2020 14:38:54 GMT

Regarding:

i have never understood why Pro did away with the VBScript option

Esri did away with VBScript because the world is doing away with VBScript. Although Microsoft hasn't formally retired VBScript, it has been an orphaned language that is dying a slow death for many years. Microsoft itself has started disabling VBScript in components of Windows operating systems.

About:

if something works better than alternatives

I am not sure which alternatives you are referring to, but Pro offers support for Python and Arcade, and both are more robust already than VBScript ever was. I personally don't like that Esri went and created yet another proprietary scripting language, but my dislike for what Esri did doesn't prevent me from seeing where the language has gotten in a relatively short time. And regarding Python, well, Python is one of the most popular scripting languages in the world and is incredibly robust and continuing to get better.

Re: ArcPro 2.5 field calculator bug

Katie_Clark — Sat, 02 May 2020 15:57:28 GMT

Joshua Bixby‌, thanks for adding your insight! I love when I actually learn something myself when helping others with their questions, it's the best part of Geonet