topic Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro in ArcGIS Pro Questions

Calculate Field Help (Python and/or SQL): ArcGIS Pro

Lebowski — Tue, 26 Nov 2019 14:26:26 GMT

So I have several field in an attribute table that have <Null> value, I am wanting to using the 'Calculate Field' GP tool to select the <Null> values and replace them with zero. Anyone have any ideas on the Python and/or SQL statement I would use to execute this?

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

JoeBorgione — Tue, 26 Nov 2019 14:59:05 GMT

The sql statement you'll use in the selection :

<YourField> is null

Your field calculator will then look like this:

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

Lebowski — Tue, 26 Nov 2019 15:01:33 GMT

I am trying to do all of this in one step either using the 'Calculate Field' GP in Pro or even better the 'Calculate Fields' GP tool in Pro. Any idea how that would look?

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

JoeBorgione — Tue, 26 Nov 2019 15:19:36 GMT

Using the tools? No. Using a python script, absolutely. What's your preference?

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

Anonymous User — Fri, 10 Dec 2021 21:38:29 GMT

Would this work for your purposes Chad? Just replace with your field name NRCS_Score or whatever in place of what I have specified for my field CENTERLINEID. This will write Zero to all NULL values:

Result of CENTERLINEID field from <NULL> to 0:

EDIT: Here is the code using your NRCS_Score field as example:

NRCS_Score =

updateValue(!NRCS_Score!)

Code Block:
def updateValue(value):
  if value == None:
   return '0'
  else: return value‍‍‍‍

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

DanPatterson_Retired — Wed, 27 Nov 2019 18:12:09 GMT

PEP 8 -- Style Guide for Python Code

For reference

if foo is None:‍

'is' is preferred to '==' as a general recommendation

Re: Calculate Field Help (Python and/or SQL): ArcGIS Pro

JoshuaBixby — Thu, 28 Nov 2019 16:41:09 GMT

The following field calculator Python expression (no Code Block necessary) should work for you:

0 if !field! is None else !field!‍