topic Re: How to Update attributes in an Online Feature Layer using Selection in ArcGIS API for Python Questions

How to Update attributes in an Online Feature Layer using Selection

ChuckBenton — Wed, 11 Aug 2021 21:55:23 GMT

I have a large feature layer hosted in ArcGIS Online. I want to select a subset by matching a field attribute to a value, and then update another field to specific value. Ideally I'd prefer not to iterate through any loops as the overall layer is > 150M records. The selection field is indexed and performs quickly, I just can't figure out how to modify/update the other field based on the selection. I've seen arcpy solutions that work with shapefiles and fgdbs, but nothing for Online.

Thanks in advance for any advice or pointers!

Re: How to Update attributes in an Online Feature Layer using Selection

DavinWalker2 — Wed, 11 Aug 2021 23:53:20 GMT

Hi Chuck,

I think FeatureLayer.calculate is what you are looking for.

Re: How to Update attributes in an Online Feature Layer using Selection

emedina — Thu, 12 Aug 2021 14:50:19 GMT

For this kind of thing, I'd recommend familiarizing yourself with Spatially Enabled DataFrames: https://developers.arcgis.com/python/guide/introduction-to-the-spatially-enabled-dataframe/

Your general process will look like this:

Create a FeatureLayer object from the layer you want to update
Create an SEDF from the FeatureLayer
Perform your selections/manipulations in the SEDF. When satisfied with the result, optionally create a version of the dataframe that only includes the field(s) you're updating and the unique identifier used for the update (ObjectID/GlobalID).
Convert the result dataframe to a feature set.
Execute an update operation with the FeatureLayer object's "edit_features" method (your update is the feature set you created).

Hope this helps.

Re: How to Update attributes in an Online Feature Layer using Selection

ChuckBenton — Thu, 12 Aug 2021 15:02:22 GMT

Thanks for the responses! featurelayer.calculate fit the bill. I'd skipped over it in my searches, because I'm not doing any "calculations". Once found it was an easy implementation. Thanks!!!

Chuck

Re: How to Update attributes in an Online Feature Layer using Selection

ChuckBenton — Thu, 12 Aug 2021 17:00:56 GMT

I'm sure this is a simple issue, but it's stumped me.

The following line executes without issue:

fs_layer.calculate(where="FIPS=18039", calc_expression={"field":"VERSION", "value": "07/04/2021"})

This fails:

where_str = '"FIPS=18039"'
calc_str = '"field":"VERSION", "value":"07/10/2021"'
fs_layer.calculate(where=where_str, calc_expression={calc_str})

I've multiple ways to build the parameters to be passed, building the entire argument, varying quote schemes. What am I missing?

Re: How to Update attributes in an Online Feature Layer using Selection

ConradSchaefer__DOIT_ — Tue, 14 Nov 2023 13:03:44 GMT

Chuck,

looks like the difference is a dict versus a set containing a string.

This is a valid dict (key: value) and looks to be an acceptable parameter type for calculate

{"field":"VERSION", "value": "07/04/2021"}

Simplifying your code your second option is:

{' "field":"VERSION", "value":"07/10/2021" '} I added spaces for clarity
notice the entire inner contents are quoted by ''
See sets https://python-reference.readthedocs.io/en/latest/docs/sets/
Your code puts a string inside of curly brackets ... calc_expression={calc_str}

Re: How to Update attributes in an Online Feature Layer using Selection

ConradSchaefer__DOIT_ — Tue, 14 Nov 2023 13:14:49 GMT

.calculate() proved to be very simple and precise. Didn't know it existed before but definitely valuable for very precise editing of individual field(s).

Re: How to Update attributes in an Online Feature Layer using Selection

FrancisCorbett — Fri, 02 Feb 2024 17:06:06 GMT

This worked great - thanks for the workflow

Re: How to Update attributes in an Online Feature Layer using Selection

MirHashmi — Fri, 16 Feb 2024 20:20:18 GMT

@DavinWalker2 Hi Davin, it not does work with me when I am passing my own value to be updated for an attribute. However, it works if I pass the column name ?

This does not work: fs_layer.calculate(where="FIPS=18039", calc_expression={"field":"FIELDNAME1", "value":"newattributevalue"}) // this returns an error PerformEdit() failure. ColumnName='newattributevalue' not found in field name map. (Error Code: 400)

This works: fs_layer.calculate(where="FIPS=18039", calc_expression={"field":"FIELDNAME1", "value":"FIELDNAME2"}) // this one copies the value from FIELDNAME2 to FIELDNAME1. Is this how calculate works?

Thank you