Update Feature with ArcGIS API for Python

[PierreWeisse1]

Hello, I work with ArcGIS API for Python on a service hosted in AGOL. I would like to update a field based on another field. I have tried many times, I do not understand how to do it. The example in the API is based on the update between two documents.

Someone to help me ?

Thank you

[simoxu · Accepted solution]

Hope the following code snippet gives you some clue:

from arcgis.gis import GIS
from arcgis.features import FeatureSet, Feature

gis = GIS(url="",username="",password="")
fs=gis.content.get(itemId)

# assume the first layer is the layer you want to update
fl=fs.layers[0]

# set return_geometry false will save you time and data 
features=fl.query(where=sql_where,out_fields='OBJECTID,FieldName'
                   ,return_geometry=False)

for feature in features:
   # Calculate the new value and assign it to the field in the current record
   feature.set_value('FieldName',NewValue)

# update the features in AGOL
results = fl.edit_features(updates=features)
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[PierreWeisse1]

Thank you Simo Xu

Have a good day

[simoxu]

You are welcome, thank you

[PierreWeisse1]

Hello Simo,

Maybe you can help me on this point. I'm still working with this web service, hosted under AGOL and with ArcGIS API for Python.

On a field of type 'date', I would like to empty the field of its contents.

However when I try, here is the result 1/1/1900 11h05

Do you have an idea ?

Thank you

[simoxu]

I don't know how you did it, but could you test whether or not the following code works? 

feature.set_value('DateFieldName',None)

[PierreWeisse1]

With your proposal it does not change. The content of the field remains the same.

Before asking for your help I tried this:

feature.set_value('DateFieldName',"")
RESULT >> 1/1/1900 11:05 AM

The field settings have this parameter.
Allow null values is set to Yes

[simoxu]

You are right.

I tried SQL in Map Viewer, it didn't work either.

I have to manually do it in AGOL Map Viewer using Arcade expression to set the Date column to NULL. But I am not sure this is what you want.

.

[JonathanPollack1]

Very nicely done.  I wish the Esri help documentation on this topic was this straightforward and to the point.